The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Jiaru Qian - One of the best experts on this subject based on the ideXlab platform.
-
Seismic Behavior and strength capacity of steel tube reinforced concrete composite columns
Earthquake Engineering & Structural Dynamics, 2014Co-Authors: Hongzhen Kang, Xingchen Chen, Jiaru QianAbstract:SUMMARY The steel tube-reinforced concrete (ST-RC) composite column is a novel type of composite column, which consists of a steel tube embedded in RC. In this paper, the Seismic Behavior of ST-RC columns is examined through a series of experiments in which 10 one-third scale column specimens were subjected to axial forces and lateral cyclic loading. The test variables include the axial force ratio applied to the columns and the amount of transverse reinforcement. All specimens failed in a flexural mode, showing stable hysteresis loops. Thanks to the steel tube and the high-strength concrete it is filled with, the ST-RC column specimens had approximately 30% lower axial force ratios and 22% higher maximum bending moments relative to the comparable RC columns when subjected to identical axial compressive loads. The amount of transverse reinforcement made only a small difference to the lateral load-carrying capacity but significantly affected the deformation and energy dissipation capacity of the ST-RC columns. The specimens that satisfied the requirements for transverse reinforcement adopted for medium ductile RC columns as specified by the Chinese Code for Seismic Design of Buildings (GB 50011-2010) and EuroCode 8 achieved an ultimate drift ratio of around 0.03 and a displacement ductility ratio of approximately 5. The design formulas used to evaluate the strength capacity of the ST-RC columns were developed on the basis of the superposition method. The predictions from the formulas showed good agreement with the test results, with errors no greater than 10%. Copyright © 2013 John Wiley & Sons, Ltd.
-
Seismic Behavior of steel tube double steel plate concrete composite walls experimental tests
Journal of Constructional Steel Research, 2013Co-Authors: Feiming Jiang, Jiaru QianAbstract:Abstract This paper proposes an innovative structural wall, named “the steel tube–double steel plate–concrete composite wall”, which is suited for use in high-rise buildings. The composite wall consists of concrete filled steel tubular (CFST) boundary elements and a double “skin” composite wall web where two steel plates are connected by tie bolts with space between them filled with concrete. The Seismic Behavior of the composite walls was examined through a series of experiments in which five slender rectangular wall specimens were subjected to axial forces and lateral cyclic loading. The specimens failed in a flexural mode, characterized by local buckling of the steel tubes and plates, fracture of the steel tubes, and concrete crushing at the wall base. The extent of the CFST boundary element was found to significantly affect the deformation and energy dissipation capacities of the walls. The area ratio of steel plates had a minimal effect on the deformation capacity of the slender walls. The addition of circular steel tubes embedded in the CFST boundary elements obviously increased the lateral load-carrying capacity of the walls. When the CFST boundary element's extent was 0.2 times the wall's sectional depth and the test axial force ratio was no more than 0.25, the walls had a yield drift ratio of over 0.005 and an ultimate drift ratio of around 0.03. Simplified formulas used to evaluate the flexure strength of the composite walls were proposed. The evaluated results had good agreement with the test results, with errors no greater than 10%.
James K Wight - One of the best experts on this subject based on the ideXlab platform.
-
Seismic Behavior and detailing of high performance fiber reinforced concrete coupling beams and coupled wall systems
Journal of Structural Engineering-asce, 2013Co-Authors: Remy D Lequesne, Gustavo J Parramontesinos, James K WightAbstract:AbstractThe Seismic Behavior of coupling beams and walls constructed with tensile strain-hardening, high-performance fiber-reinforced concrete (HPFRC) was studied through tests of large-scale precast coupling beams and coupled walls. A precast coupling beam design was developed to speed up construction and minimize interference with wall reinforcement. Three isolated precast coupling beam specimens with a span/depth of 1.75 were tested under large displacement reversals. Test results indicate the use of HPFRC allows a reduction of the reinforcement required to achieve a stable coupling beam response by providing confinement and contributing to beam shear strength. A concrete design shear stress capacity of 0.41√fc′ MPa (5√fc′ psi), where fc′ is the compressive strength of the concrete, was found to be appropriate. In addition to the coupling beam tests, two 4-story coupled wall specimens with precast HPFRC and regular concrete coupling beams were tested under lateral displacement reversals. Besides allowi...
-
experimental investigation on Seismic Behavior of eccentric reinforced concrete beam column slab connections
Aci Structural Journal, 2008Co-Authors: Burcu B Canbolat, James K WightAbstract:This paper seeks to supplement existing information on the Seismic Behavior of eccentric connections by presenting an experimental study that focused on the effect of eccentricity of spandrel beams with respect to the column. Specimens included a floor slab and transverse beams to evaluate the effect of slab participation. Test results indicated that including the floor system significantly reduced the negative influence of eccentricity. Damage was reduced, specimens had fuller load-versus-drift hysteresis loops with high energy dissipation capacities, and deterioration of joint shear stiffness and strength were delayed. The joint shear stresses resisted by the connections, without major damage, also were higher than current design values due to the participation of a larger area of the joint region in resisting shear. These findings indicate that current ACI-ASCE recommendations for effective joint width of beam-column connections in monolithic reinforced concrete structures are conservative. Since joint shear distortions contributed significantly to the total story drift for all subassemblies, accurately predicting drift demands requires a joint model that accounts for the inelastic deformations in the beam-column connections.
-
experimental study on Seismic Behavior of high performance fiber reinforced cement composite coupling beams
Aci Structural Journal, 2005Co-Authors: Afsin B Canbolat, Gustavo J Parramontesinos, James K WightAbstract:Current design provisions in the ACI Building Code for reinforced concrete (RC) coupling beams in earthquake-resistant structures require substantial reinforcement detailing to ensure a stable Seismic Behavior, leading toreinforcement congestion and construction difficulties. As a design alternative, the use of high-performance fiber-reinforced cementitious composites (HPFRCCs) in coupling beams with a simplified reinforcement detailing was experimentally investigated. To validate this alternative, four coupling beam specimens were tested, including an RC control specimen detailed as per the 1999 ACI Building Code. A precast construction process was proposed for the HPFRCC coupling beams in this study. This construction alternative would lead to significant savings in time and workmanship at the job site, and provide good material quality control. Results from large-scale tests demonstrated the superior damage tolerance and stiffness retention capacity of HPFRCC coupling beams. It was also observed that diagonal reinforcement is necessary to achieve large displacement capacity. However, the transverse reinforcement around the diagonal bars was successfully eliminated due to the confinement provided by the HPFRCC material.
Yunita Idris - One of the best experts on this subject based on the ideXlab platform.
-
Seismic Behavior of frp high strength concrete steel double skin tubular columns
Journal of Structural Engineering-asce, 2014Co-Authors: Togay Ozbakkaloglu, Yunita IdrisAbstract:AbstractThis paper reports on an experimental study on the Seismic Behavior of fiber-reinforced polymer (FRP)–concrete–steel double-skin tubular (DST) columns. Nine DST and one concrete-filled FRP-tube (CFFT) columns that were made of high-strength concrete were tested under constant axial compression and reversed-cyclic lateral loading. The main parameters of the experimental study were axial load level, amount and type of FRP confinement, concrete strength, sectional shape and thickness of the inner steel tube, and provision (or absence) of a concrete filling inside the steel tube. Of primary importance, the results indicate that DST columns are capable of developing very high inelastic deformation capacities under simulated Seismic loading. The results also indicate that the presence of a concrete filling inside the inner steel tube significantly and positively influences the Seismic Behavior of DST columns. It is found that the performance of the void-filled DST column is superior to that of a compani...
-
Seismic Behavior of high strength concrete filled frp tube columns
Journal of Composites for Construction, 2013Co-Authors: Yunita Idris, Togay OzbakkalogluAbstract:This paper reports on an experimental program that investigated the Seismic Behavior of high-strength concrete (HSC)-filled fiber-reinforced-polymer (FRP) tubes (HSCFFTs), designed to perform as building columns. Five square and one circular concrete-filled FRP tube (CFFT) columns were tested under constant axial compression and reversed-cyclic lateral loading. The main parameters of the experimental study were the axial load level, column cross-sectional shape, concrete strength, amount and type of FRP confinement, and FRP tube corner radius. Examination of the test data resulted in a number of significant conclusions with regard to the influence of the investigated column parameters on the performance of CFFT columns. Of primary importance, the results indicate that square HSCFFT columns are capable of developing very high inelastic deformation capacities under simulated Seismic loading. The results also indicate that increasing the FRP tube corner radius up to a certain threshold leads to a significant increase in column lateral drift capacities. By contrast, increasing the corner radius beyond that threshold value provides no additional improvement in the hysteretic Behavior of square CFFT columns. The influence of the cross-sectional shape is found to be significant, with the circular CFFT exhibiting a larger lateral drift capacity compared with the companion square CFFTs. A set of comparable columns from previous studies has also been included in the discussion to clarify the influence of each parameter on the column Behavior. The results of the experimental program are presented together with a discussion on the influence of the main parameters on the Seismic Behavior of CFFT columns.
Togay Ozbakkaloglu - One of the best experts on this subject based on the ideXlab platform.
-
Seismic Behavior of frp high strength concrete steel double skin tubular columns
Journal of Structural Engineering-asce, 2014Co-Authors: Togay Ozbakkaloglu, Yunita IdrisAbstract:AbstractThis paper reports on an experimental study on the Seismic Behavior of fiber-reinforced polymer (FRP)–concrete–steel double-skin tubular (DST) columns. Nine DST and one concrete-filled FRP-tube (CFFT) columns that were made of high-strength concrete were tested under constant axial compression and reversed-cyclic lateral loading. The main parameters of the experimental study were axial load level, amount and type of FRP confinement, concrete strength, sectional shape and thickness of the inner steel tube, and provision (or absence) of a concrete filling inside the steel tube. Of primary importance, the results indicate that DST columns are capable of developing very high inelastic deformation capacities under simulated Seismic loading. The results also indicate that the presence of a concrete filling inside the inner steel tube significantly and positively influences the Seismic Behavior of DST columns. It is found that the performance of the void-filled DST column is superior to that of a compani...
-
Seismic Behavior of high strength concrete filled frp tube columns
Journal of Composites for Construction, 2013Co-Authors: Yunita Idris, Togay OzbakkalogluAbstract:This paper reports on an experimental program that investigated the Seismic Behavior of high-strength concrete (HSC)-filled fiber-reinforced-polymer (FRP) tubes (HSCFFTs), designed to perform as building columns. Five square and one circular concrete-filled FRP tube (CFFT) columns were tested under constant axial compression and reversed-cyclic lateral loading. The main parameters of the experimental study were the axial load level, column cross-sectional shape, concrete strength, amount and type of FRP confinement, and FRP tube corner radius. Examination of the test data resulted in a number of significant conclusions with regard to the influence of the investigated column parameters on the performance of CFFT columns. Of primary importance, the results indicate that square HSCFFT columns are capable of developing very high inelastic deformation capacities under simulated Seismic loading. The results also indicate that increasing the FRP tube corner radius up to a certain threshold leads to a significant increase in column lateral drift capacities. By contrast, increasing the corner radius beyond that threshold value provides no additional improvement in the hysteretic Behavior of square CFFT columns. The influence of the cross-sectional shape is found to be significant, with the circular CFFT exhibiting a larger lateral drift capacity compared with the companion square CFFTs. A set of comparable columns from previous studies has also been included in the discussion to clarify the influence of each parameter on the column Behavior. The results of the experimental program are presented together with a discussion on the influence of the main parameters on the Seismic Behavior of CFFT columns.
Cuikun Wang - One of the best experts on this subject based on the ideXlab platform.
-
Experimental Study on Seismic Behavior of Full Encased Steel-Concrete Composite Columns
Journal of Structural Engineering-asce, 2014Co-Authors: Caihua Chen, Cuikun WangAbstract:AbstractWith the rapid development of high-rise buildings in China, the steel-concrete composite structure is widely used because of its excellent Seismic performance. So far, all of the high-rise buildings that rise more than 300 m in China are of a steel-concrete composite structure, which are designed based on Chinese codes. During the construction process, two main problems are encountered, as follows: (1) minimum stirrup ratio, and (2) embedded depth ratio for steel-concrete composite columns, which are strictly limited by Chinese codes. To solve those problems, 26 steel-concrete composite columns were tested under low cyclic reversed loading to simulate an earthquake load. By analyzing the failure patterns, hysteresis loops, skeleton curves, energy-dissipation capacity, and ductility of such specimens, the influence of the axial compression ratio, stirrup ratio, steel section shape, and steel embedded depth ratio on the Seismic Behavior of steel-concrete composite members are discussed. In accordanc...
