Restoring Force Model of a Cast-In-Situ Recycled Aggregate Concrete Frame

2014 ◽  
Vol 17 (10) ◽  
pp. 1443-1457 ◽  
Author(s):  
Changqing Wang ◽  
Jianzhuang Xiao ◽  
Loan Pham ◽  
Tao Ding
Keyword(s):  
Recycled Aggregate Concrete ◽  
Frame Structure ◽  
Recycled Aggregate ◽  
Force Model ◽  
Restoring Force ◽  
Skeleton Curve ◽  
Aggregate Concrete ◽  
Hysteresis Behavior ◽  
Restoring Force Model

The hysteresis behavior of a cast-in-situ recycled aggregate concrete (RAC) frame was analyzed based on shaking table tests on a one-fourth scaled model of a two-bay, two-span and 6-storey RAC frame. Then feature points and the stiffness degradation were defined and the deteriorating four-line-typed restoring force model was put forward. In the hysteresis model, the monotonic behavior is described by a four-line-typed skeleton curve which accounts for concrete cracking, yielding of reinforcing bars, maximum and ultimate point of the RAC frame model. The hysteresis behavior is described through a number of rules for unloading and reloading. Therefore, the restoring force model proposed in this study can capture the hysteresis response of the frame under seismic actions. Moreover, the displacement ductility of the RAC frame structure is evaluated based on the proposed restoring force model. It can be concluded from this investigation that the RAC frame structure with proper design and construction has favorable load-carrying capacity, deformation capacity, energy dissipation ability and seismic performance, and can be applied and popularized in the area with the requirement of aseismic fortification intensity.

scholarly journals Seismic Behavior of Concrete-Filled Circular Steel Tubular Column–Reinforced Concrete Beam Frames with Recycled Aggregate Concrete

2020 ◽  
Vol 10 (7) ◽  
pp. 2609 ◽  
Author(s):  
Zongping Chen ◽  
Ji Zhou ◽  
Zhibin Li ◽  
Xinyue Wang ◽  
Xingyu Zhou
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Seismic Behavior ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Scale Model ◽  
Hysteresis Curve ◽  
Small Scale ◽  
Skeleton Curve ◽  
Aggregate Concrete

The application of recycled aggregate concrete (RAC) in concrete filled steel tubular (CFST) structures can eliminate the deterioration of concrete performance caused by the original defects of the recycled aggregate, which also provides an effective way for the recycling of waste concrete. In this paper, a test of a small scale model of a circular CFST column-reinforced concrete (RC) beam frame with RACs under low cyclic loading was presented in order to investigate its seismic behavior. The failure modes, plastic hinges sequence, hysteresis curve, skeleton curve, energy dissipation capacity, ductility and stiffness degeneration of the frame were presented and analyzed in detail. The test results show that the design method of the recycled aggregate concrete filled circular steel tube (RACFCST) frame complies with the seismic design requirements of a stronger joint followed by the stronger column and the weaker beam. The hysteresis curve of the frame is symmetrical, showing a relatively full shuttle shape; at the same time, the ductility coefficient of the frame is greater than 2.5, showing good deformation performance. In addition, when the frame is damaged, the displacement angle is greater than 1/38, and the equivalent damping ratios coefficient is 0.243, which indicates that the frame has excellent anti-collapse and energy dissipation abilities. In summary, the RACFCST frame has good seismic behavior, which can be applied to high-rise buildings in high-intensity seismic fortification areas.

Investigation on Seismic Behavior of Recycled Aggregate Concrete Structures under Dynamic Loadings

2013 ◽  
Vol 772 ◽  
pp. 149-155
Author(s):  
Chang Qing Wang
Keyword(s):  
Seismic Behavior ◽  
Fatigue Behavior ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Recycled Aggregate Concrete ◽  
Shaking Table ◽  
Frame Structure ◽  
Recycled Aggregate ◽  
Scale Model ◽  
Aggregate Concrete

Based on the ever finished investigations of physical and mechanical properties of recycled aggregate concrete (RAC), and a series of experimental studies on the durability, the fatigue behavior, mechanical behavior and the seismic behavior of RAC components. A full scale model of a one-storey block masonry structure with tie column + ring beam + cast-in-place slab system and a one fourth scaled model of a 6-storey frame structure, which are made of reinforced recycled aggregate concrete, are tested on a shaking table by subjecting it to a series of simulated seismic ground motions, and the seismic behaviors of the RAC structures were experimentally investigated. The dynamic characteristics and the seismic response were analyzed and discussed. The overall seismic performance of RCA structures are evaluated, the analysis results show that the recycled aggregate concrete structures with proper design exhibits good seismic behavior and can resist the earthquake attacks under different earthquake levels in this study. It is feasible to apply and popularize the RAC block masonry buildings less than 2 stories and the RAC frame buildings less than 6 stories in the region where the seismic fortification intensity is 8.

scholarly journals Study on Restoring Force Performance of Corrosion Damage Steel Frame Beams under Acid Atmosphere

2018 ◽  
Vol 9 (1) ◽  
pp. 103 ◽  
Author(s):  
Bin Wang ◽  
Weizeng Huang ◽  
Shansuo Zheng
Keyword(s):  
Failure Process ◽  
Corrosion Damage ◽  
Steel Frame ◽  
Atmospheric Environment ◽  
Repeated Loading ◽  
Force Model ◽  
Test Results ◽  
Restoring Force ◽  
Skeleton Curve ◽  
Restoring Force Model

In order to study the restoring force characteristics of corroded steel frame beams in an acidic atmosphere, based on different corrosion damage degrees, tests on the material properties of 48 steel samples and six steel frame beam specimens with a scale ratio of 1/2 under low cyclic repeated loading were conducted. According to the test results, the relationship between the weight loss rate and the mechanical properties of corrosion damage steel was obtained by numerical regression analysis, and the hysteresis curves and skeleton curves of the corroded steel frame beams were also obtained. The simplified trilinear skeleton curve model of the corroded steel frame beams and the expression of the corresponding feature points were determined by analyzing the failure process. The strength and stiffness degradation rule of the steel frame beam was analyzed furtherly. The hysteresis rule was established by introducing the cyclic degradation index which considers the effect of different corrosion degrees, and finally the restoring force model based on the corroded steel frame beams in an acidic atmospheric environment was established. Comparison with the test results show that the skeleton curve and the restoring force model established in this paper can accurately describe the seismic performance of corrosion damaged steel frame beams and can provide a basis for the seismic calculation analysis of corroded steel structures in an acidic atmosphere.

scholarly journals Restoring Force Model of an Energy-Dissipation Joint in Hybrid Frames: Simplified Skeleton Curve and Hysteretic Rules

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Yanhua Wang ◽  
Yan Feng ◽  
Dongsheng Huang ◽  
Zirui Huang ◽  
Zhongfan Chen
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Critical Points ◽  
Damping Ratio ◽  
Force Model ◽  
Restoring Force ◽  
Theoretical Derivation ◽  
Skeleton Curve ◽  
Restoring Force Model ◽  
The Moment

In this paper, a restoring force model, composed of a trilinear skeleton curve and hysteretic rules, is proposed based on nine pseudostatic tests of the energy-dissipation joint under horizontal low cyclic loading. The critical points of the simplified skeleton curve are obtained via theoretical derivation and FE simulation. The hysteretic rules for the joints are simplified as a concave hexagon, where the parameters of the critical points are optimized by the genetic algorithm (GA). Using the established trilinear skeleton curve, three different working stages, i.e., elastic, hardening, and softening, were divided by the critical points and the moment stiffness of three stages can be calculated. The proposed hysteretic rules of each stage can reveal and explain the “pinching” in the cyclic loading, which make it easier to understand the mechanism of the energy-dissipation joint. The comparison between the restoring force model and the tests shows that the simplified skeleton curves, the established hysteretic rules, and the ductility and the damping ratio are consistent with the experimental results. Finally, the effectiveness of the established restoring force model is verified.

scholarly journals The Hysteresis Performance and Restoring Force Model for Corroded Reinforced Concrete Frame Columns

2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Guifeng Zhao ◽  
Meng Zhang ◽  
Yaoliang Li ◽  
Dawang Li
Keyword(s):  
Reinforced Concrete ◽  
Seismic Energy ◽  
Equivalent Model ◽  
Hysteresis Curve ◽  
Force Model ◽  
Rc Frame ◽  
Reinforced Concrete Frame ◽  
Restoring Force ◽  
Skeleton Curve ◽  
Restoring Force Model

A numerical simulation of the hysteresis performance of corroded reinforced concrete (RC) frame columns was conducted. Moreover, the results obtained were compared with experimental data. On this basis, a degenerated three-linearity (D-TRI) restoring force model was established which could reflect the hysteresis performance of corroded RC frame columns through theoretical analysis and data fitting. Results indicated that the hysteretic bearing capacity of frame columns decreased significantly due to corrosion of the rebar. In view of the characteristics of the hysteresis curve, the plumpness of the hysteresis loop for frame columns decreased and shrinkage increased with increasing rebar corrosion. All these illustrated that the seismic energy dissipation performance of frame columns reduced but their brittleness increased. As for the features of the skeleton curve, the trends for corroded and noncorroded members were basically consistent and roughly corresponded to the features of a trilinear equivalent model. Thereby, the existing Clough hysteresis rule can be used to establish the restoring force model applicable to corroded RC frame columns based on that of the noncorroded RC members. The calculated skeleton curve and hysteresis curve of corroded RC frame columns using the D-TRI model are closer to the experimental results.

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