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ART001375569
|
oai_dc
|
Adaptive balancing of highly flexible rotors by using artificial neural networks
|
Adaptive balancing of highly flexible rotors by using artificial neural networks
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Villafañe Saldarriaga(Federal University of Uberlândia); J. Mahfoud(Institut National des Sciences Appliquées de Lyon); V. Steffen Jr.(Federal University of Uberlândia); J. Der Hagopian(Institut National des Sciences Appliquées de Lyon)"
] |
The present work is an alternative methodology in order to balance a nonlinear highly flexible rotor by using neural networks. This procedure was developed aiming at improving the performance of classical balancing methods, which are developed in the context of linearity between acting forces and resulting displacements and are not well adapted to these situations. In this paper a fully experimental procedure using neural networks is implemented for dealing with the adaptive balancing of nonlinear rotors. The nonlinearity results from the large displacements measured due to the high flexibility of the foundation. A neural network based meta-model was developed to represent the system. The initialization of the learning procedure of the network is performed by using the influence coefficient method and the adaptive balancing strategy is prone to converge rapidly to a satisfactory solution. The methodology is tested successfully experimentally.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001375572
|
oai_dc
|
Static analysis of a multilayer piezoelectric actuator with bonding layers and electrodes
|
Static analysis of a multilayer piezoelectric actuator with bonding layers and electrodes
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H. J. Xiang(Beijing Jiaotong University); Z. F. Shi(Beijing Jiaotong University)"
] |
Based on the theory of piezoelasticity, an analytical solution for a typical multilayer piezoelectric composite cantilever is obtained by the Airy function method. The piezoelectric cantilever may consist of any number of layers. Moreover, the material and thickness for different layers may be different. The solution obtained in the present paper is concise and can be easily applied for the bending analysis of multilayer piezoelectric actuators considering the effect of bonding layers and electrodes. At last, a comprehensive parametric study is conducted to show the influence of electromechanical coupling (EMC), the number of piezoelectric layers, the elastic modulus of elastic layer and the thickness ratio on the bending behavior of actuators. Some interesting results for the design of multilayer piezoelectric actuators are presented.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001375574
|
oai_dc
|
Differential quadrature method for frequency analysis of membranes having irregular domains using an eight-node curvilinear element
|
Differential quadrature method for frequency analysis of membranes having irregular domains using an eight-node curvilinear element
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hakan Ersoy(Akdeniz University); Lütfiye Özpolat(Akdeniz University); Ömer Civalek(Akdeniz University); Baki Öztürk(Ni de University)"
] |
토목공학
| null |
kci_detailed_000094.xml
|
||||
ART001375573
|
oai_dc
|
Seismic performance of concrete frame structures reinforced with superelastic shape memory alloys
|
Seismic performance of concrete frame structures reinforced with superelastic shape memory alloys
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M. Shahria Alam(The University of Western Ontario); Moncef Nehdi(The University of Western Ontario); Maged A. Youssef(The University of Western Ontario)"
] |
Superelastic Shape Memory Alloys (SMAs) are gaining acceptance for use as reinforcing bars in concrete structures. The seismic behaviour of concrete frames reinforced with SMAs is being assessed in this study. Two eight-storey concrete frames, one of which is reinforced with regular steel and the other with SMAs at the plastic hinge regions of beams and regular steel elsewhere, are designed and analyzed using 10 different ground motion records. Both frames are located in the highly seismic region of Western Canada and are designed and detailed according to current seismic design standards. The validation of a finite element (FE) program that was conducted previously at the element level is extended to the structure level in this paper using the results of a shake table test of a three-storey moment resisting steel RC frame. The ten accelerograms that are chosen for analyzing the designed RC frames are scaled based on the spectral ordinate at the fundamental periods of the frames. The behaviour of both frames under scaled seismic excitations is compared in terms of maximum inter-storey drift, top-storey drift, inter-storey residual drift, and residual top-storey drift. The results show that SMA-RC frames are able to recover most of its post-yield deformation, even after a strong earthquake.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002044504
|
oai_dc
|
Incorporation preference for rubber-steel bearing isolation in retrofitting existing multi storied building
|
Incorporation preference for rubber-steel bearing isolation in retrofitting existing multi storied building
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A.B.M. Saiful Islam(University of Malaya); University of MalayaMohd Zamin Jumaat(University of Malaya); Raja Rizwan Hussain(King Saud University); Md. Akter Hosen(University of Malaya); Md. Nazmul Huda(University of Malaya)"
] |
Traditionally, multi-story buildings are designed to provide stiffer structural support to withstand lateral earthquake loading. Introducing flexible elements at the base of a structure and providing sufficient damping is an alternative way to mitigate seismic hazards. These features can be achieved with a device known as an isolator. This paper covers the design of base isolators for multi-story buildings in medium-risk seismicity regions and evaluates the structural responses of such isolators. The well-known tower building for police personnel built in Dhaka, Bangladesh by the Public Works Department (PWD) has been used as a case study to justify the viability of incorporating base isolators. The objective of this research was to establish a simplified model of the building that can be effectively used for dynamic analysis, to evaluate the structural status, and to suggest an alternative option to handle the lateral seismic load. A finite element model was incorporated to understand the structural responses. Rubber-steel bearing (RSB) isolators such as Lead rubber bearing (LRB) and high damping rubber bearing (HDRB) were used in the model to insert an isolator link element in the structural base. The nonlinearities of rubber-steel bearings were considered in detail. Linear static, linear dynamic, and nonlinear dynamic analyses were performed for both fixed-based (FB) and base isolated (BI) buildings considering the earthquake accelerograms, histories, and response spectra of the geological sites. Both the time-domain and frequency-domain approaches were used for dynamic solutions. The results indicated that for existing multi-story buildings, RSB diminishes the muscular amount of structural response compared to conventional non-isolated structures. The device also allows for higher horizontal displacement and greater structural flexibility. The suggested isolation technique is able to mitigate the structural hazard under even strong earthquake vulnerability.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002044539
|
oai_dc
|
Influence of the inclined edge notches on the shear-fracture behavior in edge-notched beam specimens
|
Influence of the inclined edge notches on the shear-fracture behavior in edge-notched beam specimens
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hadi Haeri(Islamic Azad University)"
] |
A coupled experimental and numerical study of shear fracture in the edge-notched beam specimens of quasi-brittle materials (concrete-like materials) are carried out using four point bending flexural tests. The crack initiation, propagation and breaking process of beam specimens are experimentally studied by producing the double inclined edge notches with different ligament angles in beams under four point bending. The effects of ligament angles on the shear fracturing path in the bridge areas of the double edge-notched beam specimens are studied. Moreover, the influence of the inclined edge notches on the shear-fracture behavior of double edge-notched beam specimens which represents a practical crack orientation is investigated. The same specimens are numerically simulated by an indirect boundary element method known as displacement discontinuity method. These numerical results are compared with the performed experimental results proving the accuracy and validity of the proposed study.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002044527
|
oai_dc
|
Dynamic behavior investigation of scale building renovated by repair mortar
|
Dynamic behavior investigation of scale building renovated by repair mortar
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hakan Başaran(Celal Bayar University)"
] |
The objective of this study was to examine the effect of repair mortar on the dynamic properties such as natural frequencies, mode shape and damping ratios of two story single span scale reinforced concrete building. To this end, two story single span scale reinforced concrete building having dimensions of 150 cm (width), 150 cm (length) and 135 cm (height) was constructed. Workmanship defects such as separation of material, faulty vibration application and bad gradation of the structure were properly evaluated. Dynamic properties of damaged structure were experimentally determined using Operational Modal Analysis (OMA). Detected defects in the structure were fixed by plastering with repair mortar. Dynamic properties of repaired structure were reevaluated by using the OMA method. Finite element software called Abaqus was used to numerically determine dynamic properties of the structure. Structure modeled as solid was subjected to Linear Perturbation Frequency Method. The changes in dynamic properties of structure after the repair process were comparatively studied by evaluating experimental and numerical results.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002044557
|
oai_dc
|
Flexural ductility of reinforced and prestressed concrete sections with corrugated steel webs
|
Flexural ductility of reinforced and prestressed concrete sections with corrugated steel webs
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"X.C. Chen(The University of Hong Kong); F.T.K. Au(The University of Hong Kong); Z.H. Li(Tongji University); R.J. Jiang(The University of Hong Kong)"
] |
Prestressed concrete bridges with corrugated steel webs have emerged as one of the promising bridge forms. This structural form provides excellent structural efficiency with the concrete flanges primarily taking bending and the corrugated steel webs primarily taking shear. In the design of this type of bridges, the flexural ductility and deformability as well as strength need to be carefully examined. Evaluation of these safety-related attributes requires the estimation of full-range behaviour. In this study, the full-range behaviour of beam sections with corrugated steel webs is evaluated by means of a nonlinear analytical method which uses the actual stress-strain curves of the materials and considers the path-dependence of materials. In view of the different behaviour of components and the large shear deformation of corrugated steel webs with negligible longitudinal stiffness, the assumption that plane sections remain plane may no longer be valid. The interaction between shear deformation and local bending of flanges may cause additional stress in flanges, which is considered in this study. The numerical results obtained are compared with experimental results for verification. A parametric study is undertaken to clarify the effects of various parameters on ductility, deformability and strength.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002044537
|
oai_dc
|
Discrete crack analysis for concrete structures using the hybrid-type penalty method
|
Discrete crack analysis for concrete structures using the hybrid-type penalty method
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yoshihiro Fujiwara(Hosei University); Norio Takeuchi(Hosei University); Tadahiko Shiomi(Mind Inc.); Atsushi Kambayashi(Takenaka Corporation)"
] |
The hybrid-type penalty method (HPM) is suitable for representing failure phenomena occurring during the transition from continua to discontinua in materials such as concrete. Initiation and propagation of dominant cracks and branching of cracks can easily be modeled as a discrete crack. The HPM represents a discrete crack by eliminating the penalty that represents the separation of the elements at the intersection boundary. This treatment is easy because no change in the degrees of freedom for the discrete crack is necessary. In addition, it is important to evaluate the correct deformation of the continua before the crack formation is initiated. To achieve this, we implemented a constitutive model of concrete for the HPM. In this paper, we explain the implemented constitutive model and describe the simulation of an anchor bolt pullout test using the HPM demonstrating its capability for evaluating progressive failure.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002044566
|
oai_dc
|
Simulation study on dynamic response of precast frames made of recycled aggregate concrete
|
Simulation study on dynamic response of precast frames made of recycled aggregate concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"ThiLoan Pham(Tongji University); Jianzhuang Xiao(Haiphong University); Tao Ding(Tongji University)"
] |
3-dimentional precast recycled aggregate concrete (RAC) finite element models were developed by means of the platform OpenSees to implement sophisticated nonlinear model subjected to seismic loads. Efforts were devoted to the dynamic responses (including dynamic characteristics, acceleration amplifications, displacements, story drifts) and capacity curve. In addition, this study extended the prediction on dynamic response of precast RAC model by parametric study of material properties that represent the replacement percentage of recycled coarse aggregate (RCA). Principles and assumptions that represent characteristics of precast structure and influence of the interface between head of column and cast-in-place (CIP) joint on the stiffness of the joints was put forward and validated by test results. The comparison between simulated and tested results of the precast RAC frame shows a good correlation with most of the relative errors about 25% in general. Therefore, the adopted assumptions and the platform OpenSees are a viable approach to simulate the dynamic response of precast frames made of RAC.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002044529
|
oai_dc
|
Increasing the flexural capacity of RC beams using partially HPFRCC layers
|
Increasing the flexural capacity of RC beams using partially HPFRCC layers
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ali Hemmati(Islamic Azad University); Ali Kheyroddin(Semnan University); Mohammad K. Sharbatdar(Semnan University)"
] |
High Performance Fiber Reinforced Cementitious Composites which are called HPFRCC, include cement matrices with strain hardening response under tension loading. In these composites, the cement mortar with fine aggregates, is reinforced by continuous or random distributed fibers and could be used for various applications including structural fuses and retrofitting of reinforced concrete members etc. In this paper, mechanical properties of HPFRCC materials are reviewed briefly. Moreover, a reinforced concrete beam (experimentally tested by Maalej et al.) is chosen and in different specimens, lower or upper or both parts of that beam are replaced with HPFRCC layers. After modeling of specimens in ABAQUS and calibration of those, mechanical properties of these specimens are investigated with different thicknesses, tensile strengths, tensile strains and compressive bars. Analytical results which are obtained by nonlinear finite analyses show that using HPFRCC layers with different parameters, increase loading capacity and ultimate displacement of these beams compare to RC specimens.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002044534
|
oai_dc
|
Nonlinear structural modeling using multivariate adaptive regression splines
|
Nonlinear structural modeling using multivariate adaptive regression splines
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Wengang Zhang(Nanyang Technological University); A.T.C. Goh(Nanyang Technological University)"
] |
Various computational tools are available for modeling highly nonlinear structural engineering problems that lack a precise analytical theory or understanding of the phenomena involved. This paper adopts a fairly simple nonparametric adaptive regression algorithm known as multivariate adaptive regression splines (MARS) to model the nonlinear interactions between variables. The MARS method makes no specific assumptions about the underlying functional relationship between the input variables and the response. Details of MARS methodology and its associated procedures are introduced first, followed by a number of examples including three practical structural engineering problems. These examples indicate that accuracy of the MARS prediction approach. Additionally, MARS is able to assess the relative importance of the designed variables. As MARS explicitly defines the intervals for the input variables, the model enables engineers to have an insight and understanding of where significant changes in the data may occur. An example is also presented to demonstrate how the MARS developed model can be used to carry out structural reliability analysis.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001870219
|
oai_dc
|
Optimum seismic design of unbonded post-tensioned precast concrete walls using ANN
|
Optimum seismic design of unbonded post-tensioned precast concrete walls using ANN
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jamal A. Abdalla(American University of Sharjah); Elias I. Saqan(American University in Dubai); Rami A. Hawileh(American University of Sharjah)"
] |
Precast Seismic Structural Systems (PRESSS) provided an iterative procedure for obtaining optimum design of unbonded post-tensioned coupled precast concrete wall systems. Although PRESSS procedure is effective, however, it is lengthy and laborious. The purpose of this research is to employ Artificial Neural Network (ANN) to predict the optimum design parameters for such wall systems while avoiding the demanding iterative process. The developed ANN model is very accurate in predicting the non-dimensional optimum design parameters related to post-tensioning reinforcement area, yield force of shear connectors and ratio of moment resisted by shear connectors to the design moment. The Mean Absolute Percent Error (MAPE) for the test data for these design parameters is around %1 and the correlation coefficient is almost equal to 1.0. The developed ANN model is then used to study the effect of different design parameters on wall behavior. It is observed that the design moment and the concrete strength have the most influence on the wall behavior as compared to other parameters. Several design examples were presented to demonstrate the accuracy and effectiveness of the ANN model.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001870229
|
oai_dc
|
Three-dimensional finite element modeling of a transverse top-down crack in asphalt concrete
|
Three-dimensional finite element modeling of a transverse top-down crack in asphalt concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Majid R. Ayatollahi(Iran University of Science and Technology); Sadjad Pirmohammad(Iran University of Science and Technology); Karo Sedighiani(Iran University of Science and Technology)"
] |
In this paper, a four-layer road structure consisting of an edge transverse crack is simulated using three-dimensional finite element method in order to capture the influence of a single-axle wheel load on the crack propagation through the asphalt concrete layer. Different positions of the vehicular load relative to the cracked area are considered in the analyses. Linear elastic fracture mechanics (LEFM) is used for investigating the effect of the traffic load on the behavior of a crack propagating within the asphalt concrete. The results obtained show that the crack front experiences all three modes of deformation i.e., mode I, mode II and mode III, and the corresponding stress intensity factors are highly affected by the crack geometry and the vehicle position. The results also show that for many loading situations, the contribution of shear deformation (due to mode II and mode III loading) is considerable.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001870212
|
oai_dc
|
Analytical model for CFRP strengthened circular RC column under elevated temperature
|
Analytical model for CFRP strengthened circular RC column under elevated temperature
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Raizal S.M. Rashid(Universiti Putra Malay); Riyad S. Aboutaha(L.C. Smith College)"
] |
In order to increase the load carrying capacity and/or increase the service life of existing circular reinforced concrete bridge columns, Carbon Fiber Reinforced Polymer (CFRP) composites could be utilized. Transverse wrapping of circular concrete columns with CFRP sheets increases its axial and shear strengths. In addition, it provides good confinement to the concrete column core, which enhances the bending and compressive strength, as well as, ductility. Several experimental and analytical studies have been conducted on CFRP strengthened concrete cylinders/columns. However, there seem to be lack of thorough investigation of the effect of elevated temperatures on the response of CFRP strengthened circular concrete columns. A concrete confinement model that reflects the effects of elevated temperature on the mechanical properties of CFRP composites, and the efficiency of CFRP in strengthened concrete columns is presented. Tensile strength and modulus of CFRP under hot conditions and their effects on the concrete confinement are the primary parameters that were investigated. A modified concrete confinement model is developed and presented.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001870216
|
oai_dc
|
A predictive model for compressive strength of waste LCD glass concrete by nonlinear-multivariate regression
|
A predictive model for compressive strength of waste LCD glass concrete by nonlinear-multivariate regression
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"C.C. Wang(Cheng Shiu University); T.T. Chen(National Quemoy University); H.Y. Wang(National Kaohsiung University of Applied Sciences); Chi Huang(National Kaohsiung University of Applied Sciences)"
] |
The purpose of this paper is to develop a prediction model for the compressive strength of waste LCD glass applied in concrete by analyzing a series of laboratory test results, which were obtained in our previous study. The hyperbolic function was used to perform the nonlinear-multivariate regression analysis of the compressive strength prediction model with the following parameters: water-binder ratio w/b, curing age t, and waste glass content G. According to the relative regression analysis, the compressive strength prediction model is developed. The calculated results are in accord with the laboratory measured data, which are the concrete compressive strengths of different mix proportions. In addition, a coefficient of determination R2 value between 0.93 and 0.96 and a mean absolute percentage error MAPE between 5.4% and 8.4% were obtained by regression analysis using the predicted compressive analysis value, and the test results are also excellent. Therefore, the predicted results for compressive strength are highly accurate for waste LCD glass applied in concrete. Additionally, this predicted model exhibits a good predictive capacity when employed to calculate the compressive strength of washed glass sand concrete.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001870205
|
oai_dc
|
Performance assessment of precast concrete pier cap system
|
Performance assessment of precast concrete pier cap system
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"T.H. Kim(삼성물산); Y.J. Kim(대우건설 기술연구원); 신현목(성균관대학교)"
] |
The purpose of this study was to investigate the performance of precast concrete pier cap system. The proposed precast pier cap provides an alternative to current cast-in-place systems, particularly for projects in which a reduced construction time is desired. Five large-scale pier cap specimens were constructed and tested under quasistatic monotonic loading. The computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) was used for the analysis of reinforced concrete structures. A bonded tendon element is used based on the finite element method, and can represent the interaction between the tendon and concrete of a prestressed concrete member. A joint element is used in order to predict the inelastic behaviors of segmental joints with a shear key. This study documents the testing of the precast concrete pier cap system under monotonic loading and presents conclusions and design recommendations based on the experimental and analytical findings. Additional full-scale experimental research is needed to refine and confirm design details, especially for actual detailing employed in the field.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001870201
|
oai_dc
|
Creep and shrinkage effects in service stresses of concrete cable-stayed bridges
|
Creep and shrinkage effects in service stresses of concrete cable-stayed bridges
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jose Antonio Lozano-Galant(University of Castilla-La Mancha); Jose Turmo(Universitat Politècnica de Catalunya)"
] |
Most of the methods presented in the literature to define the target service stresses (Objective Service Stage, OSS) of cable-stayed bridges rarely include the time-dependent phenomena effects. Nevertheless, especially in concrete structures, this assumption might be on the unsafe side because time-dependent phenomena usually modify service stresses. To fill this gap, this paper studies the time-dependent phenomena effects into service stresses of concrete cable-stayed bridges. After illustrating the important role of these phenomena in an asymmetrical cable-stayed bridge without backstay, a new method to include their effects into the OSS is presented. An important issue to be considered in this method is the target time in which the OSS is defined to be achieved. The application of this method to two different structures showed the convenience of defining the OSS to be achieved at early times because that way the envelope of service stresses is reduced.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001870192
|
oai_dc
|
Lattice discrete particle modeling of compressive failure in hollow concrete blocks
|
Lattice discrete particle modeling of compressive failure in hollow concrete blocks
|
{
"journal_name": "사단법인 한국계산역학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Fatemeh Javidan(Tarbiat Modares University); Sharif Shahbeyk(Tarbiat Modares University); Mohammad Safarnejad(Tarbiat Modares University)"
] |
This work incorporates newly introduced Lattice Discrete Particle Model (LDPM) to assess the failure mechanism and strength of hollow concrete blocks. Alongside, a method for the graphical representation of cracked surfaces in the LDPM is outlined. A slightly modified calibration procedure is also suggested and used to estimate required model parameters for a tested concrete sample. Next, the model is verified for a compressively loaded hollow block made of the very same concrete. Finally, four geometries commonly used in the production of hollow concrete blocks are selected, numerically simulated, and their failure properties are explored under concentric and eccentric compressions.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001870198
|
oai_dc
|
Optimal design of reinforced concrete beams: A review
|
Optimal design of reinforced concrete beams: A review
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ima Rahmanian(The University of British Columbia); Yves Lucet(The University of British Columbia); Solomon Tesfamariam(The University of British Columbia)"
] |
This paper summarizes available literature on the optimization of reinforced concrete (RC) beams. The objective of optimization (e.g. minimum cost or weight), the design variables and the constraints considered by different studies vary widely and therefore, different optimization methods have been employed to provide the optimal design of RC beams, whether as isolated structural components or as part of a structural frame. The review of literature suggests that nonlinear deterministic approaches can be efficiently employed to provide optimal design of RC beams, given the small number of variables. This paper also presents spreadsheet implementation of cost optimization of RC beams in the familiar MS Excel environment to illustrate the efficiency of the exhaustive enumeration method for such small discrete search spaces and to promote its use by engineers and researchers. Furthermore, a sensitivity analysis is performed on the contribution of various design parameters to the variability of the overall cost of RC beams.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001870189
|
oai_dc
|
Influence of Iranian low-reactivity GGBFS on the properties of mortars and concretes by Taguchi method
|
Influence of Iranian low-reactivity GGBFS on the properties of mortars and concretes by Taguchi method
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A.A. Ramezanianpour(Amirkabir University of Technology); A. Kazemian(Amirkabir University of Technology); E. Radaei(Amirkabir University of Technology); H. AzariJafari(Tabari Institute of Higher Education); M.A. Moghaddam(Amirkabir University of Technology)"
] |
Ground Granulated Blast Furnace Slag (GGBFS) is widely used as an effective partial cement replacement material. GGBFS inclusion has already been proven to improve several performance characteristics of concrete. GGBFS provides enhanced durability, including high resistance to chloride penetration and protection against alkali silica reaction. In this paper results of an experimental research work on influence of low-reactivity GGBFS (which is largely available in Iran) on the properties of mortars and concretes are reported. In the first stage, influence of GGBFS replacement level and fineness on the compressive strength of mortars was investigated using Taguchi method. The analysis of mean (ANOM) statistical approach was also adopted to develop the optimal conditions. Next, based on the obtained results, concrete mixtures were designed and water penetration, capillary absorption, surface resistivity, and compressive strength tests were carried out on high-strength concrete specimens at different ages up to 90 days. The results indicated that 7-day compressive strength is adversely affected by GGBFS inclusion, while the negative effect is less evident at later ages. Also, it was inferred that use of low-reactivity GGBFS (at moderate levels such as 20% and 30%) can enhance the impermeability of high-strength concrete since 28 days age.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001972063
|
oai_dc
|
A new approach to determine the moment-curvature relationship of circular reinforced concrete columns
|
A new approach to determine the moment-curvature relationship of circular reinforced concrete columns
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Naci Caglar(Sakarya University); Aydin Demir(Sakarya University); Hakan Ozturk(Sakarya University); Abdulhalim Akkaya(Sakarya University)"
] |
To be able to understand the behavior of reinforced concrete (RC) members, cross sectional behavior should be known well. Cross sectional behavior can be best evaluated by moment-curvature relationship. On a reinforced concrete cross section moment-curvature relationship can be best determined by both experimentally or numerically with some complicated iteration methods. Making these experiments or iterations manually is very difficult and not practical. The aim of this study is to research the efficiency of Neural Networks (NN) as a more secure and robust method to obtain the moment-curvature relationship of circular RC columns. It is demonstrated that the NN based model is highly successful to determine the moment-curvature relationship of circular reinforced concrete columns.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001972112
|
oai_dc
|
Testing of the permeability of concrete box beam with ion transport method in service
|
Testing of the permeability of concrete box beam with ion transport method in service
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jia chun Wang(Xiamen University of technology)"
] |
The permeability is the most direct indicator to reflect the durability of concrete, and the testing methods based on external electric field can be used to evaluate concrete permeability rapidly. This study aims to use an experiment method to accurately predict the permeability of concrete box beam during service. The ion migration experiments and concrete surface resistivity are measured to evaluate permeability of five concrete box beams, and the relations between these results in service concrete and electric flux after 6 hours by ASTM C1202 in the laboratory are analyzed. The chloride diffusion coefficient of concrete, concrete surface resistivity and concrete 6 hours charge have good correlation relationship, which denote that the chloride diffusion coefficient and the surface resistivity of concrete are effective for evaluating the durability of concrete structures. The chloride diffusion coefficient of concrete is directly evaluated permeability of concrete box beam in service and may be used to predict the service life, which is fit to engineering applications and the concrete box beam is non-destructive. The concrete surface resistivity is easier available than the chloride diffusion coefficient, but it is directly not used to calculate the service life. Therefore the mathematical relation of the concrete surface resistivity and the concrete chloride diffusion coefficient need to be found, which the service life of reinforced concrete is obtained by the concrete surface resistivity.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001972067
|
oai_dc
|
Tests of reinforced concrete deep beams
|
Tests of reinforced concrete deep beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Wen-Yao Lu(China University of Technology); Hsin-Tai Hsiao(China University of Technology); Chun-Liang Chen(China University of Technology); Shu-Min Huang(China University of Technology); Ming-Che Lin(China University of Technology)"
] |
This study reports the test results of twelve reinforced concrete deep beams. The deep beams were tested with loads applied through and supported by columns. The main variables studied were the shear span-to-depth ratios, and the horizontal and vertical stirrups. The shear strengths can be effectively enhanced for deep beams reinforced with both horizontal and vertical stirrups. The test results indicate the shear strengths of deep beams increase with the decrease of the shear span-to-depth ratios. The normalized shear strengths of the deep beams did not increase proportionally with an increase in effective depth. An analytical method for predicting the shear strengths of deep beams is proposed in this study. The shear strengths predicted by the proposed method and the strut-and-tie model of the ACI Code are compared with available test results. The comparison shows the proposed method can predict the shear strengths of reinforced concrete deep beams more accurately than the strut-and-tie model of the ACI Code.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001972113
|
oai_dc
|
Determination of concrete quality with destructive and non-destructive methods
|
Determination of concrete quality with destructive and non-destructive methods
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hakan Kibar(Abant Izzet Baysal University); Turgut Öztürk(Ondokuz Mayis University)"
] |
In this study, the availability of Schmidt hammer has been investigated as a reliable method to determine the quality of concrete in irrigation networks. For this purpose, the 28-day compressive strength of concrete material used in the construction irrigation channel of Bafra lowland, which is one of the most fertile plains in Turkey was examined by means of concrete compression and as well as concrete Schmidt hammer in laboratory conditions. This study was carried out on cylindrical samples to represent the everyday concrete party (150 m3) produced by contractor firm as 3 replications. The statistical analysis of experimental data showed that the correlations between the values of 28-day compressive strength of Schmidt hammer and the rebound number was found to be 0.98. Differences of the compressive strength between compression testing and Schmidt hammer were statistically significant at P<0.01. In this context, it was found that the reliability of compressive strength of the concrete compression test are excellent, also the reliability of compressive strength of Schmidt hammer are fair in assessing the quality of concrete irrigation channels.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001972069
|
oai_dc
|
Numerical modelling of nonlinear behaviour of prestressed concrete continuous beams
|
Numerical modelling of nonlinear behaviour of prestressed concrete continuous beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Tiejiong Lou(University of Coimbra); Sergio M.R. Lopes(University of Coimbra); Adelino V. Lopes(University of Coimbra)"
] |
The development of a finite element model for the geometric and material nonlinear analysis of bonded prestressed concrete continuous beams is presented. The nonlinear geometric effect is introduced by the coupling of axial and flexural fields. A layered approach is applied so as to consider different material properties across the depth of a cross section. The proposed method of analysis is formulated based on the Euler-Bernoulli beam theory. According to the total Lagrangian description, the constructed stiffness matrix consists of three components, namely, the material stiffness matrix reflecting the nonlinear material effect, the geometric stiffness matrix reflecting the nonlinear geometric effect and the large displacement stiffness matrix reflecting the large displacement effect. The analysis is capable of predicting the nonlinear behaviour of bonded prestressed concrete continuous beams over the entire loading stage up to failure. Some numerical examples are presented to demonstrate the validity and applicability of the proposed model.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001972070
|
oai_dc
|
Numerical investigation of the buckling behavior of thin ferrocement stiffened plates
|
Numerical investigation of the buckling behavior of thin ferrocement stiffened plates
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Apostolos Koukouselis(University of Thessaly); Euripidis Mistakidis(University of Thessaly)"
] |
One of the most common applications of ferrocement is the manufacturing of thin stiffened plates which are prone to buckling. This study focuses on the investigation of the behavior of a ferrocement plate, stiffened in both directions by means of an appropriate grid of ribs. In the present paper detailed three-dimensional numerical Finite Element models are formulated for the simulation of the behavior of the structure under study, which are able to take into account both the geometric and material non-linearities that are present in the subject at hand (plasticity, cracking, large displacements). The difference among the formulated models lies on the use of different types of finite elements. The numerical results obtained by each model are compared and the most efficient model is determined. Finally, this model is in the sequel used for the further investigation of the effect of different parameters on the ultimate load capacity, such as the initial out-of-plane imperfection of the plate and the interaction between the axial loads in both directions.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001972065
|
oai_dc
|
Effect of shear deformation on adhesive stresses in plated concrete beams: Analytical solutions
|
Effect of shear deformation on adhesive stresses in plated concrete beams: Analytical solutions
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mahmoud Touati(Faculté de Technologie); Abdelouahed Tounsi(University of Sidi Bel Abbes); Mohamed Benguediab(Faculté de Technologie)"
] |
In this scientific work, an improved analytical solution for adhesive stresses in a concrete beam bonded with the FRP plate is developed by including the effect of the adherend shear deformations. The analysis is based on the deformation compatibility approach where both the shear and normal stresses are assumed to be invariant across the adhesive layer thickness. The shear stress distribution is supposed to be parabolic across the depth of the adherends in computing the adhesive shear stress and Timoshenko’s beam theory is employed in predicting adhesive normal stress to consider the shear deformation. Numerical results from the present analysis are presented both to demonstrate the advantages of the present solution over existing ones and to illustrate the main characteristics of adhesive stress distributions.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001972080
|
oai_dc
|
Structural response of corroded RC beams: a comprehensive damage approach
|
Structural response of corroded RC beams: a comprehensive damage approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Irene Barbara Nina Finozzi(University IUAV of Venezia); Luisa Berto(University IUAV of Venezia); Anna Saetta(University IUAV of Venezia)"
] |
In this work, a comprehensive approach to model the structural behaviour of Reinforced Concrete (RC) beams subjected to reinforcement corrosion is proposed. The coupled environmental – mechanical damage model developed by some of the authors is enhanced for considering the main effects of corrosion on concrete, on composite interaction between reinforcement bars and concrete and on steel reinforcement. This approach is adopted for reproducing a set of experimental tests on RC beams with different corrosion degrees. After the simulation of the sound beams, the main parameters involved in the relationships characterizing the effects of corrosion are calibrated and tested, referring to one degraded beam. Then, in order to validate the proposed approach and to assess its ability to predict the structural response of deteriorated elements, several corroded beams are analyzed. The numerical results show a good agreement with the experimental ones: in particular, the proposed model properly predicts the structural response in terms of both failure mode and load-deflection curves, with increasing corrosion level.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001972107
|
oai_dc
|
Flexural behaviour of fibre reinforced geopolymer concrete composite beams
|
Flexural behaviour of fibre reinforced geopolymer concrete composite beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Vijai K(Sethu Institute of Technology); Kumutha R(P.S.R. Engineering College); Vishnuram B.G.(P.S.R. Engineering College)"
] |
An experimental investigation on the behaviour of geopolymer composite concrete beams reinforced with conventional steel bars and various types of fibres namely steel, polypropylene and glass in different volume fractions under flexural loading is presented in this paper. The cross sectional dimensions and the span of the beams were same for all the beams. The first crack load, ultimate load and the load-deflection response at various stages of loading were evaluated experimentally. The details of the finite element analysis using "ANSYS 10.0" program to predict the load-deflection behavior of geopolymer composite reinforced concrete beams on significant stages of loading are also presented. Nonlinear finite element analysis has been performed and a comparison between the results obtained from finite element analysis (FEA) and experiments were made. Analytical results obtained using ANSYS were also compared with the calculations based on theory and presented.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002029531
|
oai_dc
|
Strut-tie model for two-span continuous RC deep beams
|
Strut-tie model for two-span continuous RC deep beams
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H.S. Chae(경북대학교); 윤영묵(경북대학교)"
] |
In this study, a simple indeterminate strut-tie model which reflects complicated characteristics of the ultimate structural behavior of continuous reinforced concrete deep beams was proposed. In addition, the load distribution ratio, defined as the fraction of applied load transferred by a vertical tie of truss load transfer mechanism, was proposed to help structural designers perform the analysis and design of continuous reinforced concrete deep beams by using the strut-tie model approaches of current design codes. In the determination of the load distribution ratio, a concept of balanced shear reinforcement ratio requiring a simultaneous failure of inclined concrete strut and vertical steel tie was introduced to ensure the ductile shear failure of reinforced concrete deep beams, and the primary design variables including the shear span-to-effective depth ratio, flexural reinforcement ratio, and compressive strength of concrete were reflected upon. To verify the appropriateness of the present study, the ultimate strength of 58 continuous reinforced concrete deep beams tested to shear failure was evaluated by the ACI 318M-11's strut-tie model approach associated with the presented indeterminate strut-tie model and load distribution ratio. The ultimate strength of the continuous deep beams was also estimated by the experimental shear equations, conventional design codes that were based on experimental and theoretical shear strength models, and current strut-tie model design codes. The validity of the proposed strut-tie model and load distribution ratio was examined through the comparison of the strength analysis results classified according to the primary design variables. The present study associated with the indeterminate strut-tie model and load distribution ratio evaluated the ultimate strength of the continuous deep beams fairly well compared with those by other approaches. In addition, the present approach reflected the effects of the primary design variables on the ultimate strength of the continuous deep beams consistently and reasonably. The present study may provide an opportunity to help structural designers conduct the rational and practical strut-tie model design of continuous deep beams.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002029537
|
oai_dc
|
Prediction of curvature ductility factor for FRP strengthened RHSC beams using ANFIS and regression models
|
Prediction of curvature ductility factor for FRP strengthened RHSC beams using ANFIS and regression models
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"H. Ebrahimpour Komleh(Shahid Bahonar University of Kerman); A.A. Maghsoudi(Shahid Bahonar University of Kerman)"
] |
Nowadays, fiber reinforced polymer (FRP) composites are widely used for rehabilitation, repair and strengthening of reinforced concrete (RC) structures. Also, recent advances in concrete technology have led to the production of high strength concrete, HSC. Such concrete due to its very high compression strength is less ductile; so in seismic areas, ductility is an important factor in design of HSC members (especially FRP strengthened members) under flexure. In this study, the Adaptive Neuro-Fuzzy Inference System (ANFIS) and multiple regression analysis are used to predict the curvature ductility factor of FRP strengthened reinforced HSC (RHSC) beams. Also, the effects of concrete strength, steel reinforcement ratio and externally reinforcement (FRP) stiffness on the complete moment-curvature behavior and the curvature ductility factor of the FRP strengthened RHSC beams are evaluated using the analytical approach. Results indicate that the predictions of ANFIS and multiple regression models for the curvature ductility factor are accurate to within -0.22% and 1.87% error for practical applications respectively. Finally, the effects of height to wide ratio (h/b) of the cross section on the proposed models are investigated.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002029530
|
oai_dc
|
Concrete properties prediction based on database
|
Concrete properties prediction based on database
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Bin Chen(Zhejiang University of Water Resources); Qian Mao(Zhejiang University of Water Resources); Jingquan Gao(Zhejiang University of Water Resources); Zhaoyuan Hu(Cixi Mingfeng Building Materials Co. Ltd, Ningbo, China)"
] |
1078 sets of mixtures in total that include fly ash, slag, and/or silica fume have been collected for prediction on concrete properties. A new database platform (Compos) has been developed, by which the stepwise multiple linear regression (SMLR) and BP artificial neural networks (BP ANNs) programs have been applied respectively to identify correlations between the concrete properties (strength, workability, and durability) and the dosage and/or quality of raw materials’. The results showed obvious nonlinear relations so that forecasting by using nonlinear method has clearly higher accuracy than using linear method. The forecasting accuracy rises along with the increasing of age and the prediction on cubic compressive strength have the best results, because the minimum average relative error (MARE) for 60-day cubic compressive strength was less than 8%. The precision for forecasting of concrete workability takes the second place in which the MARE is less than 15%. Forecasting on concrete durability has the lowest accuracy as its MARE has even reached 30%. These conclusions have been certified in a ready-mixed concrete plant that the synthesized MARE of 7-day/28-day strength and initial slump is less than 8%. The parameters of BP ANNs and its conformation have been discussed as well in this study.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002029543
|
oai_dc
|
Local bond stress-slip behavior of reinforcing bars embedded in lightweight aggregate concrete
|
Local bond stress-slip behavior of reinforcing bars embedded in lightweight aggregate concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chao-Wei Tang(Cheng Shiu University)"
] |
This paper aims to study the local bond stress-slip behavior of reinforcing bars embedded in lightweight aggregate concrete (LWAC). The experimental variables of the local bond stress-slip tests include concrete strength (20, 40 and 60 MPa), deformed steel bar size (#4, #6 and #8) and coarse aggregate (normal weight aggregate, reservoir sludge lightweight aggregate and waterworks sludge lightweight aggregate). The test results show that the ultimate bond strength increased with the increase of concrete compressive strength. Moreover, the larger the rib height to the diameter ratio (h/db) of the deformed steel bars is, the greater the ultimate bond stress is. In addition, the suggestion value of the CEB-FIP Model Code to the LWAC specimen’s ultimate bond stress is more conservative than that of the normal weight concrete.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002029545
|
oai_dc
|
Determination of lateral strength and ductility characteristics of existing mid-rise RC buildings in Turkey
|
Determination of lateral strength and ductility characteristics of existing mid-rise RC buildings in Turkey
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Taner Ucar(Dokuz Eylul University); Onur Merter(Dokuz Eylul University); Mustafa Duzgun(Dokuz Eylul University)"
] |
This paper presents a comprehensive work on determination of yield base shear coefficient and displacement ductility factor of three to eight story actual reinforced concrete buildings, instead of using generic frames. The building data is provided by a walkdown survey in different locations of the pilot areas. Very detailed three dimensional models of the selected buildings are generated by using the data provided in architectural and reinforcement projects. Capacity curves of the buildings are obtained from nonlinear static pushover analyses and each capacity curve is approximated with a bilinear curve. Characteristic points of capacity curve, the yield base shear capacity, the yield displacement and the ultimate displacement capacity, are determined. The calculated values of the yield base shear coefficients and the displacement ductility factors for directions into consideration are compared by those expected values given in different versions of Turkish Seismic Design Code. Although having sufficient lateral strength capacities, the deformation capacities of these typical mid-rise reinforced concrete buildings are found to be considerably low.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002029547
|
oai_dc
|
Expansion behavior of concrete containing different steel slag aggregate sizes under heat curing
|
Expansion behavior of concrete containing different steel slag aggregate sizes under heat curing
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chun-Ya Shu(National Kaohsiung University of Applied Sciences); Wen-Ten Kuo(National Kaohsiung University of Applied Sciences)"
] |
This study investigated particle expansion in basic oxygen furnace slag (BOF) and desulfurization slag (DSS) after heat curing by using the volume method. Concrete hydration was accelerated by heat curing. The compressive strength, ultrasonic pulse velocity, and resistivity of the concrete were analyzed. Maximum expansion occurred in the BOF and DSS samples containing 0.30-0.60 mm and 0.60-1.18 mm particles, respectively. Deterioration was more severe in the BOF samples. In the slag aggregates for the complete replacement of fine aggregate, severe fractures occurred in both the BOF and DSS samples. Scanning electron microscopy revealed excess CH after curing, which caused peripheral hydration products to become extruded, resulting in fracture.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002029536
|
oai_dc
|
Seismic behavior of RC building by considering a model for shear wall-floor slab connections
|
Seismic behavior of RC building by considering a model for shear wall-floor slab connections
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mehdi Soleimani-Abiat(Shiraz University); Mohammad-Reza Banan(Shiraz University)"
] |
Connections are the most important regions in a structural system especially for buildings in seismic zones. In R.C. structures due to large dimensions of members and lack of cognition of the stress distribution in a connection, reaching a comprehensive understanding of the connection behaviors becomes more complicated. The shear wall-to-floor slab connections in lateral load resisting systems have a potential weakness in transferring loads from slabs to shear walls which might change the path of load transformation to shear walls. This paper tries to investigate the effects of seismic load combinations on the behavior of slabs at their connection zones with the shear walls. These connection zones naturally are the most critical regions of the slabs in RC buildings. The investigation carried on in a simulated environment by considering three different structures with different shear wall layout. The final results of our study reveal that layout of shear walls in a building significantly affects the magnification of forces developed at the shear wall-floor slab connections.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002029538
|
oai_dc
|
RC beams retrofitted using external bars with additional anchorages–a finite element study
|
RC beams retrofitted using external bars with additional anchorages–a finite element study
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"G. Vasudevan(Perunthalaivar Kamarajar Institute of Engineering and Technology); S. Kothandaraman(Pondicherry Engineering College)"
] |
Study on flexural retrofitting of RC beams using external bars with additional intermediate anchorages at soffit is reported in this paper. Effects of varying number of anchorages in the external bars at soffit were studied by finite element analysis using ANSYS 12.0 software. The results were also compared with available experimental results for beam with only two end anchorages. Two sets of reference and retrofitted beam specimens with two, three, four and five anchorages were analysed and the results are reported. FE modeling and non-linear analysis was carried out by discrete reinforcement modeling using Solid65, Solid45 and Link8 elements. Combin39 spring elements were used for modeling the frictional contact between the soffit and the external bars. The beam specimens were subjected to four-point bending and incremental loading was applied till failure. The entire process of modeling, application of incremental loading and generation of output in text and graphical format were carried out using ANSYS Parametric Design Language.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART002029541
|
oai_dc
|
Dynamic response of concrete gravity dams using different water modelling approaches: westergaard, lagrange and euler
|
Dynamic response of concrete gravity dams using different water modelling approaches: westergaard, lagrange and euler
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A.C. Altunisik(Karadeniz Technical University); H. Sesli(Karadeniz Technical University)"
] |
The dams are huge structures storing a large amount of water and failures of them cause especially irreparable loss of lives during the earthquakes. They are named as a group of structures subjected to fluid-structure interaction. So, the response of the fluid and its hydrodynamic pressures on the dam should be reflected more accurately in the structural analyses to determine the real behavior as soon as possible. Different mathematical and analytical modelling approaches can be used to calculate the water hydrodynamic pressure effect on the dam body. In this paper, it is aimed to determine the dynamic response of concrete gravity dams using different water modelling approaches such as Westergaard, Lagrange and Euler. For this purpose, Sarıyar concrete gravity dam located on the Sakarya River, which is 120km to the northeast of Ankara, is selected as a case study. Firstly, the main principals and basic formulation of all approaches are given. After, the finite element models of the dam are constituted considering dam-reservoir-foundation interaction using ANSYS software. To determine the structural response of the dam, the linear transient analyses are performed using 1992 Erzincan earthquake ground motion record. In the analyses, element matrices are computed using the Gauss numerical integration technique. The Newmark method is used in the solution of the equation of motions. Rayleigh damping is considered. At the end of the analyses, dynamic characteristics, maximum displacements, maximum-minimum principal stresses and maximum-minimum principal strains are attained and compared with each other for Westergaard, Lagrange and Euler approaches.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001991861
|
oai_dc
|
Permeability features of concretes produced with aggregates coated with colemanite
|
Permeability features of concretes produced with aggregates coated with colemanite
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Özlem Salli Bideci(Duzce University); Alper Bideci(Duzce University); Sabit Oymael(Istanbul Arel University); Ali Haydar Gültekin(Istanbul Technical University); Hasan Yildirim(Istanbul Technical University)"
] |
In the world total boron reserve rating, Turkey is taken place on the first rank, meeting the demand of refined mineral and main boron chemicals. Development of the new boron products and production technologies, spreading the using area of the boron are the study topics which must be finically discussed. In this study, with the help of colemanite taken in ratio as (0%, 7.5%, 12.5%, and 17.5%) by being mixed by the cement, surfaces of the pumice aggregates have been covered. Permeability of the samples has been investigated by producing lightweight concrete with 400 dose with the help of aggregates covered with colemanite. For this, the experiments of water absorption, capillary water absorption, depth of penetration of water under pressure and rapid chloride permeability have been performed. In addition, analyses of the thin section of covered and uncovered pumice aggregates and SEM (Scanning Electron Microscope) have been investigated. When the control samples produced with the covered aggregates and concretes produced with colemanite covered aggregates are compared each other, it has been determined that special lightweight concretes whose values of capillary water absorption experiment, depth of penetration of water under pressure experiment and rapid chloride permeability are low can be produced.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001991817
|
oai_dc
|
Predicting the compressive strength of cement mortars containing FA and SF by MLPNN
|
Predicting the compressive strength of cement mortars containing FA and SF by MLPNN
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Yilmaz Kocak(Dumlupinar University); Eyyup Gulbandilar(Dumlupinar University); Muammer Akcay(Dumlupinar University)"
] |
In this study, a multi-layer perceptron neural network (MLPNN) prediction model for compressive strength of the cement mortars has been developed. For purpose of constructing this model, 8 different mixes with 240 specimens of the 2, 7, 28, 56 and 90 days compressive strength experimental results of cement mortars containing fly ash (FA), silica fume (SF) and FA+SF used in training and testing for MLPNN system was gathered from the standard cement tests. The data used in the MLPNN model are arranged in a format of four input parameters that cover the FA, SF, FA+SF and age of samples and an output parameter which is compressive strength of cement mortars. In the model, the training and testing results have shown that MLPNN system has strong potential as a feasible tool for predicting 2, 7, 28, 56 and 90 days compressive strength of cement mortars.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001991854
|
oai_dc
|
Selection of measurement sets in static structural identification of bridges using observability trees
|
Selection of measurement sets in static structural identification of bridges using observability trees
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Jose Antonio Lozano-Galant(University of Castilla-La Mancha); Maria Nogal(Trinity College); Jose Turmo(Universitat Politècnica de Catalunya BarcelonaTECH); Enrique Castillo(University of Cantabria)"
] |
This paper proposes an innovative method for selection of measurement sets in static parameter identification of concrete or steel bridges. This method is proved as a systematic tool to address the first steps of Structural System Identification procedures by observability techniques: the selection of adequate measurement sets. The observability trees show graphically how the unknown estimates are successively calculated throughout the recursive process of the observability analysis. The observability trees can be proved as an intuitive and powerful tool for measurement selection in beam bridges that can also be applied in complex structures, such as cable-stayed bridges. Nevertheless, in these structures, the strong link among structural parameters advises to assume a set of simplifications to increase the tree intuitiveness. In addition, a set of guidelines are provided to facilitate the representation of the observability trees in this kind of structures. These guidelines are applied in bridges of growing complexity to explain how the characteristics of the geometry of the structure (e.g. deck inclination, type of pylon-deck connection, or the existence of stay cables) affect the observability trees. The importance of the observability trees is justified by a statistical analysis of measurement sets randomly selected. This study shows that, in the analyzed structure, the probability of selecting an adequate measurement set with a minimum number of measurements at random is practically negligible. Furthermore, even bigger measurement sets might not provide adequate SSI of the unknown parameters. Finally, to show the potential of the observability trees, a large-scale concrete cable-stayed bridge is also analyzed. The comparison with the number of measurements required in the literature shows again the advantages of using the proposed method.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001991857
|
oai_dc
|
A study on dynamic modulus of self-consolidating rubberized concrete
|
A study on dynamic modulus of self-consolidating rubberized concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mehmet Emiroğlu(Düzce University Technology); Servet Yildiz(Firat University Technology); M. Halidun Keleştemur(Meliksah University)"
] |
In this study, dynamic modulus of elasticity of self-consolidating rubberized concrete is evaluated by using results of ultrasonic pulse velocity and resonance frequency tests. Additionally, correlation between dynamic modulus of elasticity and compressive strength results is compared. For evaluating the dynamic modulus of elasticity of self-consolidating rubberized concrete, prismatic specimens having 100 x 100 x 500 mm dimensions are prepared. Dynamic modulus of elasticity values obtained by non-destructive measurements techniques are well agreed with those given in the literature.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001991859
|
oai_dc
|
Improved strut-and-tie method for 2D RC beam-column joints under monotonic loading
|
Improved strut-and-tie method for 2D RC beam-column joints under monotonic loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Xu Long(Northwestern Polytechnical University); Chi King Lee(Nanyang Technological University)"
] |
In the previous analytical studies on 2D reinforced concrete (RC) beam-column joints, the modified compression field theory (MCFT) and the strut-and-tie method (STM) are usually employed. In this paper, the limitations of these analytical models for RC joint applications are reviewed. Essentially for predictions of RC joint shear behaviour, the MCFT is not applicable, while the STM can only predict the ultimate shear strength. To eliminate these limitations, an improved STM is derived and applied to some commonly encountered 2D joints, viz., interior and exterior joints, subjected to monotonic loading.
Compared with the other STMs, the most attracting novelty of the proposed improved STM is that all critical stages of the shear stress-strain relationships for RC joints can be predicted, which cover the stages characterized by concrete cracking, transverse reinforcement yielding and concrete strut crushing. For validation and demonstration of superiority, the shear stress-strain relationships of interior and exterior RC beam-column joints from published experimental studies are employed and compared with the predictions by the proposed improved STM and other widely-used analytical models, such as the MCFT and STM.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001991814
|
oai_dc
|
Modeling of unilateral effect in brittle materials by a mesoscopic scale approach
|
Modeling of unilateral effect in brittle materials by a mesoscopic scale approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"José J.C. Pituba(Federal University of Goiás); Eduardo A. Souza Neto(Swansea University)"
] |
This work deals with unilateral effect of quasi-brittle materials, such as concrete. For this propose, a two-dimensional meso-scale model is presented. The material is considered as a three-phase material consisting of interface zone, matrix and inclusions – each constituent modeled by an appropriate constitutive model. The Representative Volume Element (RVE) consists of inclusions idealized as circular shapes randomly placed into the specimen. The interface zone is modeled by means of cohesive contact finite elements developed here in order to capture the effects of phase debonding and interface crack closure/opening. As an initial approximation, the inclusion is modeled as linear elastic as well as the matrix.
Our main goal here is to show a computational homogenization-based approach as an alternative to complex macroscopic constitutive models for the mechanical behavior of the quasi-brittle materials using a finite element procedure within a purely kinematical multi-scale framework. A set of numerical examples, involving the microcracking processes, is provided. It illustrates the performance of the proposed model. In summary, the proposed homogenization-based model is found to be a suitable tool for the identification of macroscopic mechanical behavior of quasi-brittle materials dealing with unilateral effect.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001991863
|
oai_dc
|
A reaction-diffusion modeling of carbonation process in self-compacting concrete
|
A reaction-diffusion modeling of carbonation process in self-compacting concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chuanqing Fu(Zhejiang University); Hailong Ye(The Pennsylvania State University); Xianyu Jin(Zhejiang University); Nanguo Jin(Zhejiang University); Lingli Gong(Zhejiang University)"
] |
In this paper, a reaction-diffusion model of carbonation process in self-compacting concrete (SCC) was realized with a consideration of multi-field couplings. Various effects from environmental conditions, e.g. ambient temperature, relative humidity, carbonation reaction, were incorporated into a numerical simulation proposed by ANSYS. In addition, the carbonation process of SCC was experimentally investigated and compared with a conventionally vibrated concrete (CVC). It is found that SCC has a higher carbonation resistance than CVC with a comparable compressive strength. The numerical solution analysis agrees well with the test results, indicating that the proposed model is appropriate to calculate and predict the carbonation process in SCC. The parameters sensitivity analysis also shows that the carbon dioxide diffusion coefficient and moisture field are essentially crucial to the carbonation process in SCC.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001991812
|
oai_dc
|
A damage model formulation: unilateral effect and RC structures analysis
|
A damage model formulation: unilateral effect and RC structures analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"José J.C. Pituba(Federal University of Goiás)"
] |
This work deals with a damage model formulation taking into account the unilateral effect of the mechanical behaviour of brittle materials such as concrete. The material is assumed as an initial elastic isotropic medium presenting anisotropy, permanent strains and bimodularity induced by damage evolution.
Two damage tensors governing the stiffness in tension or compression regimes are introduced. A new damage tensor in tension regimes is proposed in order to model the diffuse damage originated in prevails compression regimes. Accordingly with micromechanical theory, the constitutive model is validate when dealing with unilateral effect of brittle materials, Finally, the proposed model is applied in the analyses of reinforced concrete framed structures submitted to reversal loading. The numerical results have shown the good performance of the modelling and its potentialities to simulate practical problems in structural engineering.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001962022
|
oai_dc
|
Modeling shotcrete mix design using artificial neural network
|
Modeling shotcrete mix design using artificial neural network
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Khan Muhammad(University of Engineering & Technology); Noor Mohammad(University of Engineering & Technology); Fazal Rehman(University of Engineering & Technology)"
] |
“Mortar or concrete pneumatically projected at high velocity onto a surface” is called Shotcrete. Models that predict shotcrete design parameters (e.g. compressive strength, slump etc) from any mixing proportions of admixtures could save considerable experimentation time consumed during trial and error based procedures. Artificial Neural Network (ANN) has been widely used for similar purposes; however, such models have been rarely applied on shotcrete design. In this study 19 samples of shotcrete test panels with varying quantities of water, steel fibers and silica fume were used to determine their slump, cost and compressive strength at different ages. A number of 3-layer Back propagation Neural Network (BPNN) models of different network architectures were used to train the network using 15 samples, while 4 samples were randomly chosen to validate the model. The predicted compressive strength from linear regression lacked accuracy with R2 value of 0.36. Whereas, outputs from 3-5-3 ANN architecture gave higher correlations of R2 = 0.99, 0.95 and 0.98 for compressive strength, cost and slump parameters of the training data and corresponding R2 values of 0.99, 0.99 and 0.90 for the validation dataset. Sensitivity analysis of output variables using ANN can unfold the nonlinear cause and effect relationship for otherwise obscure ANN model.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001962023
|
oai_dc
|
Influence of flexural loading on chloride ingress in concrete subjected to cyclic drying-wetting condition
|
Influence of flexural loading on chloride ingress in concrete subjected to cyclic drying-wetting condition
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hailong Ye(Zhejiang University); Chuanqing Fu(Zhejiang University); Nanguo Jin(Zhejiang University); Xianyu Jin(Zhejiang University)"
] |
Chloride ingress implies a complex interaction between physical and chemical process, in which heat, moisture and chloride ions transport through concrete cover. Meanwhile, reinforced concrete structure itself undergoes evolution due to variation in temperature, relative humidity and creep effects, which can potentially change the deformation and trigger some micro-cracks in concrete. In addition, all of these process show time-dependent performance with complex interaction between structures and environments. In the present work, a time-dependent behavior of chloride transport in reinforced concrete beam subjected to flexural load is proposed based on the well-known section fiber model. The strain state varies because of stress redistribution caused by the interaction between environment and structure, mainly dominated by thermal stresses and shrinkage stress and creep. Finally, in order to clear the influence of strain state on the chloride diffusivity, experiment test were carried out and a power function used to describe this influence is proposed.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001962027
|
oai_dc
|
Experimental analysis and modeling of steel fiber reinforced SCC using central composite design
|
Experimental analysis and modeling of steel fiber reinforced SCC using central composite design
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Kandasamy. S(University College of Engineering); Akila. P(Govt. College of Tech)"
] |
The emerging technology of self compacting concrete, fiber reinforcement together reduces vibration and substitute conventional reinforcement which help in improving the economic efficiency of the construction. The objective of this work is to find the regression model to determine the response surface of mix proportioning Steel Fiber Reinforced Self Compacting Concrete (SFSCC) using statistical investigation. A total of 30 mixtures were designed and analyzed based on Design of Experiment (DOE). The fresh properties of SCC and mechanical properties of concrete were studied using Response Surface Methodology (RSM). The results were analyzed by limited proportion of fly ash, fiber, volume combination ratio of two steel fibers with aspect ratio of 50/35: 60/30 and super plasticizer (SP) dosage. The center composite designs (CCD) have selected to produce the response in quadratic equation. The model responses included in the primary stage were flowing ability, filling ability , passing ability and segregation index whereas in harden stage of concrete, compressive strength, split tensile strength and flexural strength at 28 days were tested. In this paper, the regression model and the response surface plots have been discussed, and optimal results were found for all the responses.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001962029
|
oai_dc
|
A 2-D numerical research on spatial variability of concrete carbonation depth at meso-scale
|
A 2-D numerical research on spatial variability of concrete carbonation depth at meso-scale
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Zichao Pan(Tongji University); Xin Ruan(Tongji University); Airong Chen(Tongji University)"
] |
This paper discusses the spatial variability of the carbonation depth caused by the mesoscopic structure of the concrete and the influence of the spatial variability on the thickness of the concrete cover. To conduct the research, a method to generate the random aggregate structure (RAS) based on polygonal particles and a simplified numerical model of the concrete carbonation at meso-scale are firstly developed. Based on the method and model, the effect of the aggregate properties including shape, content and gradation on the spatial variability of the carbonation depth is comprehensively studied. The results show that a larger degree of the spatial variability will be obtained by using (1) the aggregates with a larger aspect ratio; (2) a larger aggregate content; (3) the gradation which has more large particles. The proper sample size and model size used in the analysis are also studied. Finally, a case study is conducted to demonstrate the influence of the spatial variability of the carbonation depth on the proper thickness of the concrete cover. The research in this paper not only provides suggestions on how to decrease the spatial variability, but also proposes the method to consider the effect of the spatial variability in designing the thickness of the concrete cover.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001962032
|
oai_dc
|
Reliability analysis of reinforced concrete haunched beams shear capacity based on stochastic nonlinear FE analysis
|
Reliability analysis of reinforced concrete haunched beams shear capacity based on stochastic nonlinear FE analysis
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hasan M. Albegmprli(Gaziantep University); AbdulkadirÇevik(Gaziantep University); M. ErenGülşan(Gaziantep University); AhmetEminKurtoglu(Zirve UniversityKizilhisar Campus)"
] |
The lack of experimental studies on the mechanical behavior of reinforced concrete (RC) haunched beams leads to difficulties in statistical and reliability analyses. This study performs stochastic and reliability analyses of the ultimate shear capacity of RC haunched beams based on nonlinear finite element analysis. The main aim of this study is to investigate the influence of uncertainty in material properties and geometry parameters on the mechanical performance and shear capacity of RC haunched beams. Firstly, 65 experimentally tested RC haunched beams and prismatic beams are analyzed via deterministic nonlinear finite element method by a special program (ATENA) to verify the efficiency of utilized numerical models, the shear capacity and the crack pattern. The accuracy of nonlinear finite element analyses is verified by comparing the results of nonlinear finite element and experiments and both results are found to be in a good agreement. Afterwards, stochastic analyses are performed for each beam where the RC material properties and geometry parameters are assigned to take probabilistic values using an advanced simulating procedure. As a result of stochastic analysis, statistical parameters are determined. The statistical parameters are obtained for resistance bias factor and the coefficient of variation which were found to be equal to 1.053 and 0.137 respectively. Finally, reliability analyses are accomplished using the limit state functions of ACI-318 and ASCE-7 depending on the calculated statistical parameters. The results show that the RC haunched beams have higher sensitivity and riskiness than the RC prismatic beams.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001962035
|
oai_dc
|
Stochastic finite element based reliability analysis of steel fiber reinforced concrete (SFRC) corbels
|
Stochastic finite element based reliability analysis of steel fiber reinforced concrete (SFRC) corbels
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mehmet Eren Gulsan(Gaziantep University); Abdulkadir Cevik(Gaziantep University); AhmetEminKurtoglu(Zirve UniversityKizilhisar Campus)"
] |
In this study, reliability analyses of steel fiber reinforced concrete (SFRC) corbels based on stochastic finite element were performed for the first time in literature. Prior to stochastic finite element analysis, an experimental database of 84 sfrc corbels was gathered from literature. These sfrc corbels were modeled by a special finite element program. Results of experimental studies and finite element analysis were compared and found to be very close to each other. Furthermore experimental crack patterns of corbel were compared with finite element crack patterns and were observed to be quite similar. After verification of the finite element models, stochastic finite element analyses were implemented by a specialized finite element module. As a result of stochastic finite element analysis, appropriate probability distribution functions (PDF’s) were proposed. Finally, coefficient of variation, bias and strength reduction (resistance) factors were proposed for sfrc corbels as a consequence of stochastic based reliability analysis.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001962017
|
oai_dc
|
Effect of tube area on the behavior of concrete filled tubular columns
|
Effect of tube area on the behavior of concrete filled tubular columns
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"P.K. Gupta(Indian Institute of Technology Roorkee); V.K. Verma(Indian Institute of Technology Roorkee); Heaven Singh(Indian Institute of Technology Roorkee); Ziyad A. Khaudhair(Indian Institute of Technology Roorkee)"
] |
In the present study, a Finite Element Model has been developed and used to study the effect of diameter to wall thickness ratio (D/t) of steel tube filled with concrete under axial loading on its behavior and load carrying capacity. The model is verified by comparing its findings with available experimental results. Influence of thickness and area of steel tube on strength, ductility, confinement and failure mode shapes has been studied. Strength enhancement factors, load factor, confinement contribution, percentage of steel and ductility index are defined and introduced for the assessment. A parametric study by varying length and thickness of tube has been carried out. Diameter of tube kept constant and equals to 140 mm while thickness has been varied between 1 mm and 6 mm. Equations were developed to find out the ultimate load and confined concrete strength of concrete. Variation of lateral confining pressure along the length of concrete cylinder was obtained and found that it varies along the length. The increase in length of tubes has a minimal effect on strength of tube but it affects the failure mode shapes. The findings indicate that optimum use of materials can be achieved by deciding the thickness of steel tube. A better ductility index can be obtained with the use of higher thickness of tube.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001962052
|
oai_dc
|
Mesoscale computational simulation of the mechanical response of reinforced concrete members
|
Mesoscale computational simulation of the mechanical response of reinforced concrete members
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Licheng Wang(hina Institute of Water Resources and Hy); Jiuwen Bao(Dalian University of Technology)"
] |
On mesoscopic level, concrete can be treated as a three-phase composite material consisting of mortar, aggregates and interfacial transition zone (ITZ) between mortar and aggregate. A lot of research has confirmed that ITZ plays a crucial role in the mechanical fracture process of concrete. The aim of the present study is to propose a numerical method on mesoscale to analyze the failure mechanism of reinforced concrete (RC) structures under mechanical loading, and then it will help precisely predict the damage or the cracking initiation and propagation of concrete. Concrete is meshed by means of the Rigid Body Spring Model (RBSM) concept, while the reinforcing steel bars are modeled as beam-type elements. Two kinds of RC members, i.e. subjected to uniaxial tension and beams under bending, the fracture process of concrete and the distribution of cracks, as well as the load-deflection relationships are investigated and compared with the available test results. It is found that the numerical results are in good agreement with the experimental observations, indicating that the model can successfully simulate the failure process of the RC members.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001962026
|
oai_dc
|
Influence of softening curves on the residual fracture toughness of post-fire normal-strength concrete
|
Influence of softening curves on the residual fracture toughness of post-fire normal-strength concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Kequan YU(Tongji University); Zhou-Dao Lu(Tongji University)"
] |
The residual fracture toughness of post-fire normal-strength concrete subjected up to 600ºC is considered by the wedge splitting test. The initial fracture toughness KIini and the critical fracture toughness KIun could be calculated experimentally. Their difference is donated as the cohesive fracture toughness KIc which is caused by the distribution of cohesive stress on the fracture process zone. A comparative study on determining the residual fracture toughness associated with three bi-linear functions of the cohesive stress distribution, i.e. Peterson’s softening curve, CEB-FIP Model 1990 softening curve and Xu’s softening curve, using an analytical method is presented. It shows that different softening curves have no significant influence on the fracture toughness. Meanwhile, comparisons between the experimental and the analytical calculated critical fracture toughness values further prove the validation of the double-K fracture model to the post-fire concrete specimens.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001876718
|
oai_dc
|
Earthquake safety assessment of an arch dam using an anisotropic damage model for mass concrete
|
Earthquake safety assessment of an arch dam using an anisotropic damage model for mass concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Xinhua Xue(Sichuan University); Xingguo Yang(Sichuan University)"
] |
The seismic safety of concrete dams is one of the important problems in the engineering due to the vast socio-economic disasters which may be caused by collapse of these infrastructures. The accuracy of the risk evaluation associated with these existing dams as well as the efficient design of future dams is highly dependent on a proper understanding of their behaviour due to earthquakes. This paper develops an anisotropic damage model for arch dam under strong earthquakes. The modified Drucker-Prager criterion is adopted as the failure criteria of the dynamic damage evolution of concrete. Some process fields and other necessary information for the safety evaluation are obtained. The numerical results show that the seismic behaviour of concrete dams can be satisfactorily predicted.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001876720
|
oai_dc
|
An investigation of water magnetization and its influence on some concrete specificities like fluidity and compressive strength
|
An investigation of water magnetization and its influence on some concrete specificities like fluidity and compressive strength
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"N. Khorshidi(Sahand University); M. Ansari(Tarbiat Modares University); M. Bayat(Islamic Azad University)"
] |
In this paper, effects of magnetic water on different properties of cement paste including fluidity, compressive strength, time of setting and etc, has been studied in concrete laboratory of Sahand University of Technology. For production of magnetic water, three devices including an AFM called device(made in UAE) ,a device marked AC(made in Germany) and finally a device was designed and made in Concrete Laboratory of Sahand University of Technology) have been used. The results show that, intensity and direction of magnetic field, velocity and time of water passing through magnetic device, and amount and type of Colloidal particles have direct effects on properties of magnetic water and using such a water in making cement paste, increases its fluidity and compressive strength up to 10%.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001876721
|
oai_dc
|
Bayesian updated correlation length of spatial concrete properties using limited data
|
Bayesian updated correlation length of spatial concrete properties using limited data
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Pieterjan Criel(Magnel Laboratory for Concrete Research); Robby Caspeele(Magnel Laboratory for Concrete Research); Luc Taerwe(Magnel Laboratory for Concrete Research)"
] |
A Bayesian response surface updating procedure is applied in order to update the parameters of the covariance function of a random field for concrete properties based on a limited number of available measurements. Formulas as well as a numerical algorithm are presented in order to update the parameters of response surfaces using Markov Chain Monte Carlo simulations. The parameters of the covariance function are often based on some kind of expert judgment due the lack of sufficient measurement data. However, a Bayesian updating technique enables to estimate the parameters of the covariance function more rigorously and with less ambiguity. Prior information can be incorporated in the form of vague or informative priors. The proposed estimation procedure is evaluated through numerical simulations and compared to the commonly used least square method.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001876723
|
oai_dc
|
Investigation of nonlinear behaviour of reinforced concrete frames having different stiffening members
|
Investigation of nonlinear behaviour of reinforced concrete frames having different stiffening members
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Şenol Gürsoy(Karabük University)"
] |
The selected carrier systems of reinforced concrete frame buildings are quite important on structural damages. In this study are examined comparatively nonlinear behaviours of reinforced concrete frames which having different stiffening members under a horizontal load. In that respect, the study consists of six parametric models. With this purpose, nonlinear structural analyses of reinforced concrete frames which having different stiffening members were carried out with LUSAS which uses the finite element method. Thus, some conclusions and recommendations to mitigate the damage of reinforced concrete buildings in the future designs are aimed to present. The obtained results revealed that in terms of performance, the x-shaped diagonal elements can be used as an option to shear walls. In addition, it was found that frame-2, frame-3 and frame-4 showed a better performance than traditional frame system (frame-1).
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001876713
|
oai_dc
|
Modeling of post-tensioned one-way and two-way slabs with unbonded tendons
|
Modeling of post-tensioned one-way and two-way slabs with unbonded tendons
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Uksun Kim(California State University at Fullerton); Yu Huang(The University of Oklahoma); Pinaki R. Chakrabarti(California State University at Fullerton); 강현구(서울대학교)"
] |
A sophisticated finite element modeling approach is proposed to simulate unbonded post-tensioned concrete slabs. Particularly, finite element contact formulation was employed to simulate the sliding behavior of unbonded tendons. The contact formulation along with other discretizing schemes was selected to assemble the post-tensioned concrete system. Three previously tested unbonded post-tensioned two-way and one-way slabs with different reinforcement configurations and boundary conditions were modeled. Numerical results were compared against experimental data in terms of global pressure-deflection relationship, stiffness degradation, cracking pattern, and stress variation in unbonded tendons. All comparisons indicate a very good agreement between the simulations and experiments. The exercise of model validation showcased the robustness and reliability of the proposed modeling approach applied to numerical simulation of post-tensioned concrete slabs.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001876716
|
oai_dc
|
Implication of rubber- steel bearing nonlinear models on soft storey structures
|
Implication of rubber- steel bearing nonlinear models on soft storey structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"A.B.M. Saiful Islam(University of Malaya); Raja Rizwan Hussain(King Saud University); Mohammed Zamin Jumaat(University of Malaya); Kh Mahfuz ud Darain(University of Malaya)"
] |
Soft storey buildings are characterised by having a storey that has a large amount of open space. This soft storey creates a major weak point during an earthquake. As the soft stories are typically associated with retail spaces and parking garages, they are often on the lower levels of tall building structures. Thus, when these stories collapse, the entire building can also collapse, causing serious structural damage that may render the structure completely unusable. The use of special soft storey is predominant in the tall building structures constructed by several local developers, making the issue important for local building structures. In this study, the effect of the incorporation of an isolator on the seismic behaviour of tall building structures is examined. The structures are subjected to earthquakes typical of the local city, and the isolator is incorporated with the appropriate isolator time period and damping ratio. A FEM-based computational relationship is proposed to increase the storey height so as to incorporate the isolator with the same time period and damping ratio for both a lead rubber bearing (LRB) and high-damping rubber bearing (HDRB). The study demonstrates that the values of the FEM-based structural design parameters are greatly reduced when the isolator is used. It is more beneficial to incorporate a LRB than a HDRB.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001876717
|
oai_dc
|
Prediction of compressive strength for HPC mixes containing different blends using ANN
|
Prediction of compressive strength for HPC mixes containing different blends using ANN
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Allam Lingam(National Institute of Technology); J.Karthikeyan(National Institute of Technology)"
] |
This paper is aimed at adapting Artificial Neural Networks (ANN) to predict the compressive strength of High Performance Concrete (HPC) containing binary and quaternary blends. The investigations were done on 23 HPC mixes, and specimens were cast and tested after 7, 28 and 56 days curing. The obtained experimental datas of 7, 28 and 56 days are trained using ANN which consists of eight input parameters like cement, metakaolin, blast furnace slag and fly ash, fine aggregate, coarse aggregate, superplasticizer and water binder ratio. The corresponding output parameters are 7, 28 and 56 days compressive strengths. The predicted values obtained using ANN show a good correlation between the Experimental data. The performance of the 8-9-3-3 architecture was better than other architectures. It concluded that ANN tool is convenient and time saving for predicting compressive strength at different ages.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001923008
|
oai_dc
|
Nonlinear finite element modelling of centric dowel connections in precast buildings
|
Nonlinear finite element modelling of centric dowel connections in precast buildings
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Blaž Zoubek(Gebze Institute of Technology,); Yasin Fahjan(Gebze Institute of Technology,); Matej Fischinger(University of Ljubljana); Tatjana Isaković(University of Ljubljana)"
] |
The modelling approach in the case of connections in precast buildings is specific. The assembly of the constitutive parts of the connection requires the inclusion of contact definitions in the model. In addition, the material non-linearity including the influence of the spatial stress distribution should be takeninto account where appropriate. Here a complex model of a beam-to-column dowel connection is presented. Experiments on the analysed connection were performed within the framework of the European project SAFECAST (Performance of Innovative Mechanical Connections in Precast Building Structures under Seismic Conditions). Several material and interaction parameters were investigated and the influence of each of them was evaluated. The set of parameters which gave the best match with the experiments was chosen.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001922995
|
oai_dc
|
Comparative investigation of the costs and performances of torsional irregularity structures under seismic loading according to TEC
|
Comparative investigation of the costs and performances of torsional irregularity structures under seismic loading according to TEC
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Şenol Gürsoy(Karabük University)"
] |
The poor seismic performance of reinforced concrete buildings during the latest earthquakes has become a serious issue in the building industry in Turkey. This case, designing new buildings without structural irregularities against earthquake loads reveals to be quite significant. This study mainly is focused on the effects of different torsional irregularities on construction costs and earthquakes performance of reinforced concrete buildings. In that respect, structural torsional irregularities are investigated based on the Turkish Earthquake Code. The study consists of major eight main parametric models. In this models consist of totally 49 models together with the variations in the number of storey. With this purpose, the earthquake performances and construction costs (especially steel quantities) of reinforced concrete buildings which having different structural torsional irregularities were obtained with the help of Sta4-CAD program. Each model has been analyzed by both the methods of equivalent earthquake loading and dynamic analysis. The obtained results reveal that the model-1 which has lower torsional irregularity coefficient shows the best earthquake performance owing to its regular plan geometry. Also, economical comparisons on costs of the torsional irregularity are performed, and results-recommendations are given.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001923012
|
oai_dc
|
Shear strength of RC beams. Precision, accuracy, safety and simplicity using genetic programming
|
Shear strength of RC beams. Precision, accuracy, safety and simplicity using genetic programming
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Antoni Cladera(University of the Balearic Islands); Juan L. Pérez-Ordóñez(University of A Coruña); Fernando Martínez-Abella(University of A Coruña, Campus de Elviña)"
] |
This paper presents the improvement of the EC-2 and EHE-08 shear strength formulations for concrete beams with shear reinforcement. The employed method is based on the genetic programming (GP) technique, which is configured to generate symbolic regression from a set of experimental data by considering the interactions among precision, accuracy, safety and simplicity. The size effect and the influence of the amount of shear reinforcement are examined. To develop and verify the models, 257 experimental tests on concrete beams from the literature are used. Three expressions of considerablesimplicity, which significantly improve the shear strength prediction with respect to the formulations of the different studied codes, are proposed.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001922991
|
oai_dc
|
Numerical analysis for behavior of outer concrete tank in emergency LNG spillage
|
Numerical analysis for behavior of outer concrete tank in emergency LNG spillage
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"이정수(명지대학교); 박찬규(삼성물산); 이윤(대전대학교); 김지훈(삼성물산); 권승희(명지대학교)"
] |
In the existing method for analyzing the liquid tightness of the outer concrete tank in an emergency LNG spillage, the temperature variation over time inside the tank, and the concrete properties dependent on temperature and internal moisture content, have not been taken into account. In this study, the analyses for a typical LNG concrete tank subjected to thermal load due to spillage were performed with three different cases: the existing method was adopted in the first case, the transient temperature variation was considered in the second, and the temperature-moisture content dependent concrete properties were taken into account as well as the transient states of temperature in the third. The analysis results for deformation, compressive zone size, cracking, and stress of reinforcements were compared, and a discussion on the difference between the results obtained from the different analysis cases was made.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001922997
|
oai_dc
|
Long-term flexural cracking control of reinforced self- compacting concrete one way slabs with and without fibres
|
Long-term flexural cracking control of reinforced self- compacting concrete one way slabs with and without fibres
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Farhad Aslani(University of New South Wales); Shami Nejadi(University of Technology Sydney); Bijan Samali(University of Western Sydney)"
] |
In this study experimental result of a total of eight SCC and FRSCC slabs with the same cross-section were monitored for up to 240 days to measure the time-dependent development of cracking and deformations under service loads are presented. For this purpose, four SCC mixes are considered in the test program. This study aimed to compare SCC and FRSCC experimental results with conventional concrete experimental results. The steel strains within the high moment regions, the concrete surface strains at thetensile steel level, deflection at the mid-span, crack widths and crack spacing were recorded throughout the testing period. Experimental results show that hybrid fibre reinforced SCC slabs demonstrated minimum instantaneous and time-dependent crack widths and steel fibre reinforced SCC slabs presented minimum final deflection.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001923000
|
oai_dc
|
Optimal design of reinforced concrete plane frames using artificial neural networks
|
Optimal design of reinforced concrete plane frames using artificial neural networks
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chin-Sheng Kao(Tamkang University); I-Cheng Yeh(Tamkang University)"
] |
To solve structural optimization problems, it is necessary to integrate a structural analysis package and an optimization package. There have been many packages that can be employed to analyze reinforced concrete plane frames. However, because most structural analysis packages suffer from closeness of systems, it is very difficult to integrate them with optimization packages. To overcome the difficulty, we proposed a possible alternative, DAMDO, which integrates Design, Analysis, Modeling, Definition, and Optimization phases into an integration environment as follows. (1) Design: first generate many possible structural design alternatives. Each design alternative consists of many design variables X. (2) Analysis: employ the structural analysis software to analyze all structural design alternatives to obtain their internal forces and displacements. They are the response variables Y. (3) Modeling: employ artificial neural networks to build the models Y=f(X) to obtain the relationship functions between the design variables X and the response variables Y. (4) Definition: employ the design variables X and the response variables Y to define the objective function and constraint functions. (5) Optimization: employ the optimization software to solve the optimization problem consisting of the objective function and the constraint functions to produce the optimum design variables. The RC frame optimization problem was examined to evaluate the DAMDO approach, and the empirical results showed that it can be solved by the approach.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001922993
|
oai_dc
|
Structural performance assessment of deteriorated reinforced concrete bridge piers
|
Structural performance assessment of deteriorated reinforced concrete bridge piers
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"T.H. Kim(삼성물산)"
] |
The aim of this study is to assess the structural performance of deteriorated reinforced concrete bridge piers, and to provide method for developing improved evaluation method. For a deteriorated bridge piers, once the cover spalls off and bond between the reinforcement and concrete has been lost, compressed reinforcements are likely to buckle. By using a sophisticated nonlinear finite element analysis program, the accuracy and objectivity of the assessment process can be enhanced. A computer program, RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology), is used to analyze reinforced concrete structures. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. Advanced deteriorated material models are developed to predict behaviors of deteriorated reinforced concrete. The proposed numerical method for the structural performance assessment of deteriorated reinforced concrete bridge piers is verified by comparing it with reliable experimental results. Additionally, the studies and discussions presented in this investigation provide an insight into the key behavioral aspects of deteriorated reinforced concrete bridge piers.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001913571
|
oai_dc
|
Automated segmentation of concrete images into microstructures: A comparative study
|
Automated segmentation of concrete images into microstructures: A comparative study
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mehran Yazdi(Shiraz University); Katayoon Sarafrazi(Shiraz University)"
] |
Concrete is an important material in most of civil constructions. Many properties of concrete can be determined through analysis of concrete images. Image segmentation is the first step for the most of these analyses. An automated system for segmentation of concrete images into microstructures using texture analysis is proposed. The performance of five different classifiers has been evaluated and the results show that using an Artificial Neural Network classifier is the best choice for an automatic image segmentation of concrete.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001913506
|
oai_dc
|
Fuzzy logic approach for estimating bond behavior of lightweight concrete
|
Fuzzy logic approach for estimating bond behavior of lightweight concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Mehmet E. Arslan(Düzce University); Ahmet Durmuş(Karadeniz Technical University)"
] |
In this paper, a rule based Mamdani type fuzzy logic model for prediction of slippage at maximum tensile strength and slippage at rupture of structural lightweight concretes were discussed. In the model steel rebar diameters and development lengths were used as inputs. The FL model and experimental results, the coefficient of determination R2, the Root Mean Square Error were used as evaluation criteria for comparison. It was concluded that FL was practical method for predicting slippage at maximum tensile strength and slippage at rupture of structural lightweight concretes.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001913526
|
oai_dc
|
Prediction of ions migration behavior in mortar under 2-D ALMT application to inhibit ASR
|
Prediction of ions migration behavior in mortar under 2-D ALMT application to inhibit ASR
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chih-Chien Liu(ROC Military Academy); Wen-Ten Kuo(National Kaohsiung University of Applied Sciences)"
] |
This study investigated four electric field configurations of two-dimensional accelerate lithium migration technique (ALMT), including line-to-line, plane-to-line, contour-to-line and plane-to-plane, and analyzed the ion migration behavior and efficiency. It was found that the free ion distribution diagram and voltage distribution diagram were similar, and ions migrated in the power line direction. The electrode modules were used for the mortar specimen with w/c ratio of 0.5. The effectively processed areas accounted for 14.1%, 39.0%, 49.4% and 51.4% of total area respectively on Day 28. Larger electrode area was more advantageous to ion migration. In addition, it was proved that the two-dimensional electric field could be divided into different equifield line active regions, and regarded as affected by one-dimensional electric field, and the ion migration results in various equifield line active regions were predicted by using the duration analysis method based on the theoretical model of ion migration obtained from one-dimensional test.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001913551
|
oai_dc
|
Effects of confinement reinforcement and concrete strength on nonlinear behaviour of RC buildings
|
Effects of confinement reinforcement and concrete strength on nonlinear behaviour of RC buildings
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Burak Yön(Fırat University); Yusuf Calayır(Fırat University)"
] |
This paper investigates the effects of confinement reinforcement and concrete strength on nonlinear behaviour of reinforced concrete buildings (RC). For numerical application, an eleven-storey and four bays reinforced concrete frame building is selected. Nonlinear incremental static (pushover) analyses of the building are performed according to various concrete strengths and whether appropriate confinement reinforcement, which defined in Turkish seismic code, exists or not at structural elements. In nonlinear analysis, distributed plastic hinge model is used. As a result of analyses, capacity curves of the frame building and moment-rotation curves at lower end sections of ground floor columns are determined. These results are compared with each other according to concrete strength and whether appropriate confinement reinforcement exists or not, respectively. According to results, it is seen that confinement reinforcement is important factor for increasing of building capacity and decreasing of rotations at structural elements.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001913521
|
oai_dc
|
Prediction of compressive strength of slag concrete using a blended cement hydration model
|
Prediction of compressive strength of slag concrete using a blended cement hydration model
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"왕소용(강원대학교); 이한승(한양대학교)"
] |
Partial replacement of Portland cement by slag can reduce the energy consumption and CO2 emission therefore is beneficial to circular economy and sustainable development. Compressive strength is the most important engineering property of concrete. This paper presents a numerical procedure to predict the development of compressive strength of slag blended concrete. This numerical procedure starts with a kinetic hydration model for cement–slag blends by considering the production of calcium hydroxide in cement hydration and its consumption in slag reactions. Reaction degrees of cement slag are obtained as accompanied results from the hydration model. Gel-space ratio of hardening slag blended concrete is determined using reaction degrees of cement and slag, mixing proportions of concrete, and volume stoichiometries of cement hydration and slag reaction. Furthermore, the development of compressive strength is evaluated through Powers’ gel-space ratio theory considering the contributions of cement hydration and slag reaction. The proposed model is verified through experimental data on concrete with different water-to-binder ratios and slag substitution ratios.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001913487
|
oai_dc
|
Web-shear capacity of prestressed hollow-core slab unit with consideration on the minimum shear reinforcement requirement
|
Web-shear capacity of prestressed hollow-core slab unit with consideration on the minimum shear reinforcement requirement
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"이득행(서울시립대학교); 박민국(서울시립대학교); 오재율(서울시립대학교); 김강수(서울시립대학교); 임주혁(서울시립대학교); 서수연(한국교통대학교)"
] |
Prestressed hollow-core slabs (HCS) are widely used for modern lightweight precast floor structures because they are cost-efficient by reducing materials, and have excellent flexural strength and stiffness by using prestressing tendons, compared to reinforced concrete (RC) floor system. According to the recently revised ACI318-08, the web-shear capacity of HCS members exceeding 315 mm in depth without the minimum shear reinforcement should be reduced by half. It is, however, difficult to provide shear reinforcement in HCS members produced by the extrusion method due to their unique concrete casting methods, and thus, their shear design is significantly affected by the minimum shear reinforcement provision in ACI318-08. In this study, a large number of shear test data on HCS members has been collected and analyzed to examine their web-shear capacity with consideration on the minimum shear reinforcement requirement in ACI318-08. The analysis results indicates that the minimum shear reinforcement requirement for deep HCS members are too severe, and that the web-shear strength equation in ACI318-08 does not provide good estimation of shear strengths for HCS members. Thus, in this paper, a rational web-shear strength equation for HCS members was derived in a simple manner, which provides a consistent margin of safety on shear strength for the HCS members up to 500 mm deep. More shear test data would be required to apply the proposed shear strength equation for the HCS members over 500 mm in depth though.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001913562
|
oai_dc
|
Effect of fiber type and content on properties of high-strength fiber reinforced self-consolidating concrete
|
Effect of fiber type and content on properties of high-strength fiber reinforced self-consolidating concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Bui Le Anh Tuan(Can Tho University); Mewael Gebregirogis Tesfamariam(National Taiwan University of Science an); Chao-Lung Hwang(National Taiwan University of Science and Technology); Chun-Tsun Chen(National Taiwan University of Science and Technology); Yuan-Yuan Chen(Hwa-sha Institue of Technology); Kae-Long Lin(National Ilan University)"
] |
Effects of polypropylene (PP) fibers, steel fibers (SF) and hybrid on the properties of high-strength fiber reinforced self-consolidating concrete (HSFR-SCC) under different volume contents are investigated in this study. Comprehensive laboratory tests were conducted in order to evaluate both fresh and hardened properties of HSFR-SCC. Test results indicated that the fiber types and fiber contents greatly influenced concrete workability but it is possible to achieve self consolidating properties while adding the fiber types in concrete mixtures. Compressive strength, dynamic modulus of elasticity, and rigidity of concrete were affected by the addition as well as volume fraction of PP fibers. However, the properties of concrete were improved by the incorporation of SF. Splitting tensile and flexural strengths of concrete became increasingly less influenced by the inclusion of PP fibers and increasingly more influenced by the addition of SF. Besides, the inclusion of PP fibers resulted in the better efficiency in the improvement of toughness than SF. Furthermore, the inclusion of fibers did not have significant effect on the durability of the concrete. Results of electrical resistivity, chloride ion penetration and ultrasonic pulse velocity tests confirmed that HSFR-SCC had enough endurance against deterioration, lower chloride ion penetrability and minimum reinforcement corrosion rate.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001913575
|
oai_dc
|
Prediction of the bond strength of ribbed steel bars in concrete based on genetic programming
|
Prediction of the bond strength of ribbed steel bars in concrete based on genetic programming
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Emadaldin Mohammadi Golafshani(Amirkabir University of Technology); Alireza Rahai(Amirkabir University of Technology); Seyedeh Somayeh Hosseini Kebria(Amirkabir University of Technology)"
] |
This paper presents the application of multi-gene genetic programming (MGP) technique for modeling the bond strength of ribbed steel bars in concrete. In this regard, the experimental data of 264 splice beam tests from different technical papers were used for training, validating and testing the model. Seven basic parameters affecting on the bond strength of steel bars were selected as input parameters. These parameters are diameter, relative rib area and yield strength of steel bar, minimum concrete cover to bar diameter ratio, splice length to bar diameter ratio, concrete compressive strength and transverse reinforcement index. The results show that the proposed MGP model can be alternative approach for predicting the bond strength of ribbed steel bars in concrete. Moreover, the performance of the developed model was compared with the building codes' empirical equations for a complete comparison. The study concludes that the proposed MGP model predicts the bond strength of ribbed steel bars better than the existing building codes' equations. Using the proposed MGP model and building codes' equations, a parametric study was also conducted to investigate the trend of the input variables on the bond strength of ribbed steel bars in concrete.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001883849
|
oai_dc
|
Application of artificial neural networks for dynamic analysis of building frames
|
Application of artificial neural networks for dynamic analysis of building frames
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Shardul G. Joshi(Vishwakarma Institute of Information Technology); Shreenivas N. Londhe(Vishwakarma Institute of Information Technology); Naveen Kwatra(Thapar University)"
] |
Many building codes use the empirical equation to determine fundamental period of vibration where in effect of length, width and the stiffness of the building is not explicitly accounted for. In the present study, ANN models are developed in three categories, varying the number of input parameters in each category. Input parameters are chosen to represent mass, stiffness and geometry of the buildings indirectly.
Total numbers of 206 buildings are analyzed out of which, data set of 142 buildings is used to develop these models. It is demonstrated through developed ANN models that geometry of the building and the sizes of the columns are significant parameters in the dynamic analysis of building frames. The testing dataset of these three models is used to obtain the empirical relationship between the height of the building and fundamental period of vibration and compared with the similar equations proposed by other researchers. Experiments are conducted on Mild Steel frames using uniaxial shake table. It is seen that the values obtained through the ANN models are close to the experimental values. The validity of ANN technique is verified by experimental values.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001883842
|
oai_dc
|
Short term bond shear stress and cracking control of reinforced self-compacting concrete one way slabs under flexural loading
|
Short term bond shear stress and cracking control of reinforced self-compacting concrete one way slabs under flexural loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Farhad Aslani(University of New South Wales); Shami Nejadi(University of Technology Sydney); Bijan Samali(University of Western Sydney)"
] |
Fibre-reinforced self-compacting concrete (FRSCC) is a high-performance building material that combines positive aspects of fresh properties of self-compacting concrete (SCC) with improved characteristics of hardened concrete as a result of fibre addition. To produce SCC, either the constituent materials or the corresponding mix proportions may notably differ from the conventional concrete (CC).
These modifications besides enhance the concrete fresh properties affect the hardened properties of the concrete. Therefore, it is vital to investigate whether all the assumed hypotheses about CC are also valid for SCC structures. In the present paper, the experimental results of short-term flexural load tests on eight reinforced SCC and FRSCC specimens slabs are presented. For this purpose, four SCC mixes – two plain SCC, two steel, two polypropylene, and two hybrid FRSCC slab specimens – are considered in the test program. The tests are conducted to study the development of SCC and FRSCC flexural cracking under increasing short-term loads from first cracking through to flexural failure. The achieved experimental results give the SCC and FRSCC slabs bond shear stresses for short-term crack width calculation. Therefore, the adopted bond shear stress for each mix slab is presented in this study. Crack width, crack patterns, deflections at mid-span, steel strains and concrete surface strains at the steel levels were recorded at each load increment in the post-cracking range.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001883851
|
oai_dc
|
Investigating deformations of RC beams: experimental and analytical study
|
Investigating deformations of RC beams: experimental and analytical study
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Javier Ezeberry Parrotta(Polytechnic University of Madrid); Hugo Corres Peiretti(Polytechnic University of Madrid); Viktor Gribniak(Vilnius Gediminas Technical University); Alejandro Pérez Caldentey(Polytechnic University of Madrid)"
] |
In this paper, a theoretical and experimental study of the sectional behaviour of reinforced concrete beams subjected to short-term loads is carried out. The pure bending behaviour is analysed with moment-curvature diagrams. Thus, the experimental results obtained from 24 beams tested by the authors and reported in literature are compared with theoretical results obtained from a layered model, which combines the material parameters defined in Model Code 2010 with some of the most recognized tensionstiffening models. Although the tests were carried out for short-term loads, the analysis demonstrates that rheological effects can be important and must be accounted to understand the experimental results. Another important conclusion for the beams tested in this work is that the method proposed by EC-2 tends to underestimate the tension-stiffening effects, leading to inaccuracies in the estimations of deflections. Thus, the actual formulation is analysed and a simple modification is proposed. The idea is the separation of the deflection prediction in two parts: one for short-term loads and other for rheological effects (shrinkage). The results obtained are in fairly good agreement with the experimental results, showing the feasibility of the proposed modification.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001883835
|
oai_dc
|
Chloride binding isotherms of various cements basing on binding capacity of hydrates
|
Chloride binding isotherms of various cements basing on binding capacity of hydrates
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Tran Van Mien(HoChiMinh City University of Technology); Toyoharu Nawa(Hokkaido University); Boonchai Stitmannaithum(Chulalongkorn University)"
] |
This study investigated the chloride binding isotherms of various cement types, especially the contributions of C-S-H and AFm hydrates to the chloride binding isotherms were determined. Ordinary Portland cement (OPC), Modified cement (MC), Rapid-hardening Portland cement (RHC) and Low-heat Portland cement (LHC) were used. The total chloride contents and free chloride contents were analyzed by ASTM. The contents of C-S-H, AFm hydrates and Friedel’s salt were determined by X-ray diffraction Rietveld (XRD Rietveld) analysis. The results showed that OPC had the highest chloride binding capacity, and, LHC had the lowest binding capacity of chloride ions. MC and RHC had very similar capacities to bind chloride ions. Experimental equations which distinguish the chemically bound chloride and physically bound chloride were formulated to determine amounts of the bound chloride basing on chloride binding capacity of hydrates.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001883850
|
oai_dc
|
Method for estimating workability of self-compacting concrete using mixing process images
|
Method for estimating workability of self-compacting concrete using mixing process images
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Xuehui An(Tsinghua University); Shuyang Li(Tsinghua University,)"
] |
Estimating the workability of self-compacting concrete (SCC) is very important both in laboratories and on construction site. A method using visual information during the mixing process was proposed in this paper to estimate the workability of SCC. First, fourteen specimens of concrete were produced by a single-shaft mixer. A digital camera was used to record all the mixing processes. Second, employing the digital image processing, the visual information from mixing process images was extracted. The concrete pushed by the rotating blades forms two boundaries in the images. The shape of the upper boundary and the vertical distance between the upper and lower boundaries were used as two visual features. Thirdly, slump flow test and V-funnel test were carried out to estimate the workability of each SCC. Finally, the vertical distance between the upper and lower boundaries andthe shape of the upper boundary were used as indicators to estimate the workability of SCC. The vertical distance between the upper and lower boundaries was related to the slump flow, the shape of the upper boundary was related to the V-funnel flow time. Based on these relationships, the workability of SCC could be estimated using the mixing process images. This estimating method was verified by three more experiments. The experimental results indicate that the proposed method could be used to automatically estimate SCC workability.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001883847
|
oai_dc
|
The use of artificial neural networks in predicting ASR of concrete containing nano-silica
|
The use of artificial neural networks in predicting ASR of concrete containing nano-silica
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ramin Tabatabaei(Islamic Azad University); Hamid Reza Sanjari(Islamic Azad University); Mohsen Shamsadini(Islamic Azad University)"
] |
In this article, by using experimental studies and artificial neural network has been tried to investigate the use of nano-silica as concrete admixture to reduce alkali-silica reaction. If there are reactive aggregates and alkali of cement with enough moisture in concrete, a gel will be formed. Then with high reactivity between alkali of cement and existence of silica in aggregates, this gel will expand by absorption of water, and causes expansive pressure and cracks be formed. At the time passes, this gel will reduce bothdurability and strength of the concrete. By reducing the size of silicate to nano, specific surface area of particles and number of atoms on the surface will be increased, which causes more pozzolanic activity of them. Nano-silica can react with calcium hydroxide (Ca (OH)2) and produces C-S-H gel. In this study,accelerated mortar bar specimens according to ASTM C 1260 and ASTM C 1567, with different mix proportions were prepared using aggregates of Kerman, such as: none admixture and plasticizer, differentproportions of nano-silica separately. By opening the moulds after 24 hour and curing in water at 80 °C for 24 hour, then curing in (1N NaOH) at 80 °C for 14 days, length expansion of mortar bars were measured and compared. It was noted that, the lowest length expansion of a specimens shows the best proportion of admixture based on alkali-silica reactivity. Then, prediction of alkali-silica reaction of concrete has been investigated by using artificial neural network. In this study the backpropagation network has been used and compared with different algorithms to train network. Finally, the best amount of nano silica for adding to mix proportion, also the best algorithm and number of neurons in hidden layer of artificial neural network have been offered.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001883848
|
oai_dc
|
Effect of brick infill panel on the seismic safety of reinforced concrete frames under progressive collapse
|
Effect of brick infill panel on the seismic safety of reinforced concrete frames under progressive collapse
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hamidreza Tavakoli(BabolNoshirvani University of Technology); Soodeh Akbarpoor(Mazandaran University of Science& Technology)"
] |
Structural safety has always been a key preoccupation for engineers responsible for the design of civil engineering projects. One of the mechanisms of structural failure, which has gathered increasing attention over the past few decades, is referred to as ‘progressive collapse’ which happens when one or several structural members suddenly fail, whatever the cause (accident, attack, seismic loading(.Any weakness in design or construction of structural elements can induce the progressive collapse in structures,during seismic loading. Masonry infill panels have significant influence on structure response against the lateral load. Therefore in this paper, seismic performance and shear strength of R.C frames with brick infill panel under various lateral loading patterns are investigated. This evaluation is performed by nonlinear static analysis. The results provided important information for additional design guidance on seismic safety of RC frames with brick infill panel under progressive collapse.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001859344
|
oai_dc
|
Numerical investigation on tortuosity of transport paths in cement-based materials
|
Numerical investigation on tortuosity of transport paths in cement-based materials
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Xiao-Bao Zuo(Nanjing University of Science & Technology); Wei Sun(Southeast University); Zhi-Yong Liu(Yantai University); Yu-Juan Tang(Nanjing University of Science & Technology)"
] |
Based on the compositions and structures of cement-based materials, the geometrical models of the tortuosity of transport paths in hardened cement pastes, mortar and concrete, which are associated withthe capillary porosity, cement hydration degree, mixture particle shape, aggregate volume fraction andwater-cement ratio, are established by using a geometric approach. Numerical simulations are carried out to investigate the effects of material parameters such as water-cement ratio, volume fraction of the mixtures, shape and size of aggregates and cement hydration degree, on the tortuosity of transport paths in hardened cement pastes, mortar and concrete. Results indicate that the transport tortuosity in cement-based materials decreases with the increasing of water-cement ratio, and increases with the cement hydration degree, the volume fraction of cement and aggregate, the shape factor and diameter of aggregates, and the material parameters related to cement pastes, such as the water-cement ratio, cement hydration degree and cement volume fraction, are the primary factors that influence the transport tortuosity of cement-based materials.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001859345
|
oai_dc
|
Producing synthetic lightweight aggregates by treating waste TFT-LCD glass powder and reservoir sediments
|
Producing synthetic lightweight aggregates by treating waste TFT-LCD glass powder and reservoir sediments
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chao-Wei Tang(Cheng Shiu University)"
] |
The use of lightweight aggregate (LWA) instead of ordinary aggregate may make lightweight aggregate concrete, which possesses many advantages such as lightweight, lower thermal conductivity, and better fire and seismic resistance. Recently the developments of LWA have been focused on using industrial wastes as raw materials to reduce the use of limited natural resources. In view of this, the intent of this studywas to apply Taguchi optimization technique in determining process condition for producing synthetic LWA by incorporating waste thin film transition liquid crystal displays (TFT-LCD) glass powder with reservoir sediments. In the study the waste TFT-LCD glass cullet was used as an additive. It was incorporated with reservoir sediments to produce LWA. Taguchi method with an orthogonal array L16(45) and five controllable 4-level factors (i.e., cullet content, preheat temperature, preheat time, sintering temperature, and sintering time) was adopted. Then, in order to optimize the selected parameters, the analysis of variance method was used to explore the effects of the experimental factors on the performances (particle density, water absorption, bloating ratio, and loss of ignition) of the produced LWA. The results showed that it is possible to produce high performance LWA by incorporating waste TFT-LCD glass cullet with reservoir sediments. Moreover, Taguchi method is a promising approach for optimizing process condition of synthetic LWA using recycled glass cullet and reservoir sediments and it significantly reduces the number of tests.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001859349
|
oai_dc
|
Genetic algorithm optimization of precast hollow core slabs
|
Genetic algorithm optimization of precast hollow core slabs
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Luca Sgambi(Politecnico di Milano); Konstantinos Gkoumas(Sapienza University of Rome); Franco Bontempi(Sapienza University of Rome)"
] |
Precast hollow core slabs (HCS) are technically advanced products in the precast concrete industry, widely used in the last years due to their versatility, their multipurpose potential and their low cost. Using three dimensional FEM (Finite Element Method) elements, this study focuses on the stresses induced by the prestressing of steel. In particular the investigation of the spalling crack formation that takes place during prestressing is carried out, since it is important to assure the appropriate necessary margins concerning such stresses. In fact, spalling cracks may spread rapidly towards the web, leading to the detachment of the lower part of the slab. A parametric study takes place, capable of evaluating the influence of the tendon position and of the web width on the spalling stress. Consequently, after an extensive literature review on the topic of soft computing, an optimization of the HCS is performed by means of Genetic Algorithms coupled with 3-D FEM models.
|
토목공학
| null |
kci_detailed_000094.xml
|
|||
ART001859350
|
oai_dc
|
Bonding between high strength rebar and reactive powder concrete
|
Bonding between high strength rebar and reactive powder concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Deng Zong-cai(Beijing University of Technology); Jumbe R.Daud(Beijing University of Technology); Yuan Chang-xing(Beijing University of Technology)"
] |
A central pullout test was conducted to investigate the bonding properties between high strength rebar and reactive powder concrete (RPC), which covered ultimate pullout load, ultimate bonding stress, free end initial slip, free end slip at peak load, and load-slip curve characteristics. The effects of varying rebar buried length, thickness of protective layer and diameter of rebars on the bonding properties were studied, and how to determine the minimum thickness of protective layer and critical anchorage length was suggested according the test results. The results prove that: 1) Ultimate pull out load and free end initial slip load increases with increase in buried length, while ultimate bonding stress and slip corresponding to the peak load reduces. When buried length is increased from 3d to 4d(d is the diameter of rebar), after peak load, the load-slip curve descending segment declines faster, but later the load rises again exceeding the first peak load. When buried length reaches 5d, rebar pull fracture occurs. 2) As thickness of protective layer increases, the ultimate pull out load, ultimate bond stress, free end initial slip load and the slip corresponding to the peak load increase, and the descending section of the curve becomes gentle. The recommended minimum thickness of protective layer for plate type members should be the greater value between d and 10 mm, and for beams or columns the greater value between d and 15 mm. 3) Increasing the diameter of HRB500 rebars leads to a gentle slope in the descending segment of the pullout curve. 4) The bonding properties between high strength steel HRB500 and RPC is very good. The suggested buried length for test determining bonding strength between high strength rebars and RPC is 4d and a formula to calculate the critical anchorage length is established. The relationships between ultimate bonding stress and thickness of protective layer or the buried length was obtained.
|
토목공학
| null |
kci_detailed_000095.xml
|
|||
ART001859348
|
oai_dc
|
An experimental study on different socket base connections under cyclic loading
|
An experimental study on different socket base connections under cyclic loading
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Selim Pul(Karadeniz Technical University); Metin Hüsem(Karadeniz Technical University); Mehmet Emin Arslan(Karadeniz Technical University); Sertaç Hamzaçebi(Karadeniz Technical University)"
] |
This paper presents an experimental study on socket base connections of precast reinforced concrete columns. The main purpose of this study is to determine socket base connection which has the closest behavior to monolithic casted column-base joints. For this purpose, six specimens having different column-socket base connection details were tested under cyclic loading. For each test, strength, stiffness, ductility and drift ratios of the specimens were determined. Test results indicated that a suggested connection type is 10% - 30% stronger than the other type of connections under lateral loading. The welded connection (PC-5) had better lateral load carrying capacity and ductility. On the other hand, performance of standard connection (PC-1) which is commonly used in construction was weaker than other connections. Thus, decision of connection type should be referred not only performance but also applicability.
|
토목공학
| null |
kci_detailed_000095.xml
|
|||
ART001859346
|
oai_dc
|
An efficient numerical simulation of the cyclic loading experiments on RC structures
|
An efficient numerical simulation of the cyclic loading experiments on RC structures
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Georgios Ch. Lykidis(National Technical University of Athens); Konstantinos V. Spiliopoulos(National Technical University of Athens)"
] |
In this work a numerical method to simulate the response of reinforced concrete structures subject to cyclically imposed displacements is proposed. The method consists of a combination of a displacement and load controlled version of the Newton–Raphson iterative technique, used for the loading and the unloading part of the cycles respectively. The whole procedure is combined with a relatively simple concrete model whose only material parameter is its uniaxial compressive strength. The proposed methodology may realistically simulate, in an easy way, the physical process of any experimentally tested RC structure under imposed displacements cycles. The efficiency of the approach is demonstrated through a series of analyses of experimentally tested specimens reported in the literature.
|
토목공학
| null |
kci_detailed_000095.xml
|
|||
ART001859347
|
oai_dc
|
Nonlinear calculation of moisture transport in underground concrete
|
Nonlinear calculation of moisture transport in underground concrete
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"M.F. Ba(Ningbo University); C.X. Qian(Southeast University); G.B.Gao(Shandong Provincial Academy of Building Research)"
] |
The moisture transport in underground concrete was experimentally investigated and the nonlinear model of moisture transport considering the effects of water diffusion, hydration of cementicious materials and water permeability was proposed. The consumed moisture content by self-desiccation could be firstly calculated according to evolved hydration degree of cement and mineral admixtures. Furthermore, the finite differential method was adopted to solve the moisture transport model by linearizing the nonlinear moisture diffusion coefficient. The comparison between experimental and calculated results showed a good agreement, which indicated that the proposed moisture model could be used to predict moisture content evolution in underground concrete members with drying–wetting boundaries.
|
토목공학
| null |
kci_detailed_000095.xml
|
|||
ART002071783
|
oai_dc
|
Modeling of damage in cement paste subject to external sulfate attack
|
Modeling of damage in cement paste subject to external sulfate attack
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Chuansheng Xiong(Hohai University); Linhua Jiang(Hohai University); Yan Zhang(Hohai University); Hongqiang Chu(Hohai University)"
] |
This study aimed to develop models of sulfate diffusion and ettringite content profile in cement paste for the predication of the damage behavior in cement paste subject to external sulfate. In the models, multiphase reaction equilibrium between ions in pore solution and solid calcium aluminates phases and the microstructure changes in different positions of cement paste were taken into account.
The distributions of expansive volume strain and expansion stress in cement paste were calculated based on the ettringite content profile model. In addition, more sulfate diffusion tests and SEM analyses were determined to verify the reliability and veracity of the models. As the results shown, there was a good correlation between the numerical simulation results and experimental evidences. The results indicated that the water to cement ratio (w/c) had a significant influence on the diffusion of sulfate ions, ettringite concentration profile and expansion properties in cement paste specimens. The cracking points caused by ettringite growth in cement paste specimens were predicted through numerical methods. According to the simulation results, the fracture of cement paste would be accelerated when the specimens were prepared with higher w/c or when they were exposed to sulfate solution with higher concentration.
|
토목공학
| null |
kci_detailed_000095.xml
|
|||
ART002071786
|
oai_dc
|
Modified electrical conductivity test method for evaluation concrete permeability
|
Modified electrical conductivity test method for evaluation concrete permeability
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Amirreza Pilvar(Amirkabir University of Technology); Ali Akbar Ramezanianpour(Amirkabir University of Technology); Hosein Rajaie(Amirkabir University of Technology)"
] |
Standard test method for bulk electrical conductivity (ASTM C1760) provides a rapid indication of the concrete’s resistance to the penetration of chloride ions by diffusion. In this paper a new approach for assessing the bulk electrical conductivity of saturated specimens of hardened concrete is presented. The test involves saturating concrete specimens with a 5 M NaCl solution before measuring the conductivity of the samples. By saturating specimens with a highly conductive solution, they showed virtually the same pore solution conductivity. Different concrete samples yield different conductivity primarily due to differences in their pore structure. The feasibility of the method has been demonstrated by testing different concrete mixtures consisting ordinary and blended cement of silica fume (SF) and calcined perlite powder (CPP). Two standard test methods of RCPT (ASTM C1202) and Bulk Conductivity (ASTM C1760) were also applied to all of the samples. The results show that for concretes containing SF and CPP, the proposed method is less sensitive towards the variations in the pore solution conductivity in comparison with RCPT and Bulk Conductivity tests. It seems that this method is suitable for the assessment of the performance and durability of different concretes containing supplementary cementitious materials.
|
토목공학
| null |
kci_detailed_000095.xml
|
|||
ART002071780
|
oai_dc
|
Shear performance assessment of steel fiber reinforcedprestressed concrete members
|
Shear performance assessment of steel fiber reinforcedprestressed concrete members
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"황진하(서울시립대학교); 이득행(University of Illinois at Urbana - Champaign); 박민국(서울시립대학교); 최승호(서울시립대학교); 김강수(서울시립대학교); Zuanfeng Pan(Tongji University)"
] |
In this study, shear tests on steel fiber reinforced-prestressed concrete (SFR-PSC) members were conducted with test parameters of the concrete compressive strength, the volume fraction of steel fibers, and the level of effective prestress. The SFR-PSC members showed higher shear strengths and stiffness after diagonal cracking compared to the conventional prestressed concrete (PSC) members without steel fibers. In addition, their shear deformational behavior was measured using the imagebased non-contact displacement measurement system, which was then compared to the results of nonlinear finite element analyses (NLFEA). In the NLFEA proposed in this study, a bi-axial tensile behavior model, which can reflect the tensile behavior of the steel fiber-reinforced concrete (SFRC) in a simple manner, was introduced into the smeared crack truss model. The NLFEA model proposed in this study provided a good estimation of shear behavior of the SFRPSC members, such as the stiffness, strengths, and failure modes, reflecting the effect of the key influential factors.
|
토목공학
| null |
kci_detailed_000095.xml
|
|||
ART002071787
|
oai_dc
|
Experimental crack analyses of concrete-like CSCBD specimens using a higher order DDM
|
Experimental crack analyses of concrete-like CSCBD specimens using a higher order DDM
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Hadi Haeri(Islamic Azad University)"
] |
A simultaneous analytical, experimental and numerical analysis of crack initiation, propagation and breaking process of the Central Straight through Crack Brazilian Disk (CSCBD) specimens under diametrical compression is carried out. Brazilian disc tests are being accomplished to evaluate the fracturing process based on stress intensity factors (SIFs). The effects of crack inclination angle and crack length on the fracturing processes have been investigated. The same experimental specimens have been numerically modeled by a higher order indirect boundary element method (HDDM). These numerical results are compared with the existing experimental results proving the accuracy and validity of the proposed numerical method.
|
토목공학
| null |
kci_detailed_000095.xml
|
|||
ART002071795
|
oai_dc
|
Creep of concrete at variable stresses and heating
|
Creep of concrete at variable stresses and heating
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Sergei Klovanych(University of Warmia and Mazury in Olsztyn)"
] |
This article gives analytical dependences for creep of concrete at heating, taking into account conditions of its drying. These dependences are based on the standard nonlinear theory of creep of concrete at a normal temperature and temperature-time analogy. For the description of creep at various stresses and temperatures the principle of superposition are used. All stages of model’s creation are confirmed by the existing experimental data. Calculation examples are given.
|
토목공학
| null |
kci_detailed_000095.xml
|
|||
ART002071799
|
oai_dc
|
Bond behavior of lightweight concretes containing coated pumice aggregate: hinged beam approach
|
Bond behavior of lightweight concretes containing coated pumice aggregate: hinged beam approach
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Ahmet Beycioğlu(Technology Faculty Düzce University); Mehmet E. Arslan(Technology Faculty Düzce University); Özlem S. Bideci(Art-Design and Architecture Faculty); Alper Bideci(Art-Design and Architecture Faculty); Mehmet Emiroğlu(Technology Faculty Düzce University)"
] |
This paper presents an experimental study for determining the bond performance of lightweight concretes produced using pumice aggregate coated with colemanite-cement paste. For this purpose, eight hinged beam specimens were produced with four different concrete mixtures. 14 mm deformed bars with 10Ф development lengths were selected constant for all test specimens. All the specimens were tested in bending and load-slip values were measured experimentally to determine the effect of colemanite-cement coated pumice aggregate on bond performances of lightweight concretes.
Test results showed that, colemanite-cement coated pumice aggregate increases compressive strength and bond performance of the lightweight concretes, considerably.
|
토목공학
| null |
kci_detailed_000095.xml
|
|||
ART002071804
|
oai_dc
|
Non-destructive assessment of the three-point-bending strength of mortar beams using radial basis function neural networks
|
Non-destructive assessment of the three-point-bending strength of mortar beams using radial basis function neural networks
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Alex Alexandridis(Technological Educational Institute of Athens); Ilias Stavrakas(Technological Educational Institute of Athens); Charalampos Stergiopoulos(Technological Educational Institute of Athens); George Hloupis(Technological Educational Institute of Athens); Konstantinos Ninos(Technological Educational Institute of Athens); Dimos Triantis(Technological Educational Institute of Athens)"
] |
This paper presents a new method for assessing the three-point-bending (3PB) strength of mortar beams in a non-destructive manner, based on neural network (NN) models. The models are based on the radial basis function (RBF) architecture and the fuzzy means algorithm is employed for training, in order to boost the prediction accuracy. Data for training the models were collected based on a series of experiments, where the cement mortar beams were subjected to various bending mechanical loads and the resulting pressure stimulated currents (PSCs) were recorded. The input variables to the NN models were then calculated by describing the PSC relaxation process through a generalization of Boltzmannn-Gibbs statistical physics, known as non-extensive statistical physics (NESP). The NN predictions were evaluated using k-fold cross-validation and new data that were kept independent from training; it can be seen that the proposed method can successfully form the basis of a non-destructive tool for assessing the bending strength. A comparison with a different NN architecture confirms the superiority of the proposed approach.
|
토목공학
| null |
kci_detailed_000095.xml
|
|||
ART002071807
|
oai_dc
|
Application of a mesh-free method to modelling brittle fracture and fragmentation of a concrete column during projectile impact
|
Application of a mesh-free method to modelling brittle fracture and fragmentation of a concrete column during projectile impact
|
{
"journal_name": "국제구조공학회",
"publisher": null,
"pub_year": null,
"pub_month": null,
"volume": null,
"issue": null
}
|
[
"Raj Das(University of Auckland); Paul W. Cleary(Informatics and Statistics)"
] |
Damage by high-speed impact fracture is a dominant mode of failure in several applications of concrete structures. Numerical modelling can play a crucial role in understanding and predicting complex fracture processes. The commonly used mesh-based Finite Element Method has difficulties in accurately modelling the high deformation and disintegration associated with fracture, as this often distorts the mesh.
Even with careful re-meshing FEM often fails to handle extreme deformations and results in poor accuracy.
Moreover, simulating the mechanism of fragmentation requires detachment of elements along their boundaries, and this needs a fine mesh to allow the natural propagation of damage/cracks. Smoothed Particle Hydrodynamics (SPH) is an alternative particle based (mesh-less) Lagrangian method that is particularly suitable for analysing fracture because of its capability to model large deformation and to track free surfaces generated due to fracturing. Here we demonstrate the capabilities of SPH for predicting brittle fracture by studying a slender concrete structure (column) under the impact of a high-speed projectile. To explore the effect of the projectile material behaviour on the fracture process, the projectile is assumed to be either perfectly-elastic or elastoplastic in two separate cases. The transient stress field and the resulting evolution of damage under impact are investigated. The nature of the collision and the constitutive behaviour are found to considerably affect the fracture process for the structure including the crack propagation rates, and the size and motion of the fragments. The progress of fracture is tracked by measuring the average damage level of the structure and the extent of energy dissipation, which depend strongly on the type of collision. The effect of fracture property (failure strain) of the concrete due to its various compositions is found to have a profound effect on the damage and fragmentation pattern of the structure.
|
토목공학
| null |
kci_detailed_000095.xml
|
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