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 Residual Properties Analysis of Steel Reinforced Recycled Aggregate Concrete Components after Exposure to Elevated Temperature

2018 ◽  
Vol 8 (12) ◽  
pp. 2377 ◽  
Author(s):  
Zongping Chen ◽  
Rusheng Yao ◽  
Chenggui Jing ◽  
Fan Ning
Keyword(s):  
Elevated Temperature ◽  
Energy Dissipation ◽  
Mass Loss ◽  
Bearing Capacity ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Residual Properties ◽  
Significant Fluctuation ◽  
Capacity Degradation

The application of recycled aggregate concrete (RAC) has developed rapidly in recent years. But how to evaluate the residual properties of RAC after the fires is more beneficial to the further popularization and application of RAC. This paper presents the residual properties of RAC and steel reinforced recycled aggregate concrete (SRRAC) components after exposure to elevated temperature. A total of 176 specimens (120 rectangular prisms specimens, 24 SRRAC short columns and 32 SRRAC beams) were designed and tested after exposure to elevated temperature. The parameters were considered in the test, including replacement percentage of recycled coarse aggregate (0%, 30%, 50%, 70% and 100%) and exposure to different temperatures (20, 200, 400, 600 and 800 degrees centigrade). According to the test results, heat damage and residual properties of specimens were analyzed in detail, such as surface change, mass loss, bearing capacity degradation, stiffness degradation, ductility and energy dissipation of specimens under the elevated temperature. The results showed that a series of significant physical phenomena occurred on the surface of RAC and SRRAC components after exposure to elevated temperature, such as the color changed from green-grey to gray-white, chapped on the concrete surface after 400 degrees centigrade and the mass loss of concrete is less than 10%. The degradation of mechanical properties degenerated significantly with the increase of temperature, such as the strength of RAC, and compressive capacity, bending capacity, shear capacity and stiffness of SRRAC components, among that, the degradation of the strength of RAC was most obvious, up to 26%. The ductility and energy dissipation of SRRAC components were insignificant affected by the elevated temperature. Mass loss ratio, peak deformation and bearing capacity showed a slight increase trend with the increase of replacement percentage. But the stiffness showed significant fluctuation when replacement percentage was 70% to 100%. And the ductility and energy dissipation showed significant fluctuation when replacement percentage was 30% to 70%.

scholarly journals Effect of Recycled Aggregates on the Energy Dissipation Capacity of RC Beam subjected to Reverse Cyclic Flexural Loading

2021 ◽  
Vol 40 (1) ◽  
pp. 140-151
Author(s):  
Muhammad Rizwan Riaz ◽  
Rashid Hameed ◽  
Usman Akmal ◽  
Asad Ali Gillani ◽  
Muhammad Ilyas
Keyword(s):  
Energy Dissipation ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Rc Beam ◽  
Rc Beams ◽  
Aggregate Concrete ◽  
Flexural Loading ◽  
Energy Dissipation Capacity ◽  
Natural Aggregates

The energy dissipation capacity of concrete is an important aspect for a Reinforced Concrete (RC) structure to be seismically resistant. Various types of concrete incorporating sustainable materials are being developed these days such as recycled aggregate concrete. Determination of energy dissipation capacity of such new types of concrete is of great importance for their application in RC structures which are to be constructed in seismically active areas. In this regard, the experimental study presented in this contribution investigated the energy dissipation capacity of RC beams constructed using recycled aggregate concrete and subjected to three different deflection amplitude levels of reverse cyclic flexural loading. For this purpose, a total of 20 RC beams of cross section 75 x 150 mm and length of 1350 mm were cast using five different concrete compositions and tested. Among five different concrete compositions, one was control concrete containing 100% natural aggregates while the remaining four compositions were of recycled aggregate concrete containing natural and recycled aggregates. Four replacement levels (25%, 50%, 75%, and 100%) of natural aggregates with recycled aggregates were examined. Results indicated that the amplitude level of imposed deflection is an important factor which influenced the value of energy dissipated by RC beams. Further, results showed that RC beam constructed using recycled aggregate concrete containing 25% recycled aggregates exhibited energy dissipation capacity similar to or even better than that of control RC beam containing 100% natural aggregates.

scholarly journals Call for papers on special issue “Performance-based Service Life Design of reinforced recycled aggregate concrete”

2020 ◽  
Vol 2 (1) ◽  
pp. 045-045
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Chloride Ion ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Special Issue ◽  
Aggregate Concrete ◽  
Service Life Design ◽  
Life Design

Aim & Scope: Sustainability requires a judicious use of natural resources. Reducing the consumption of natural aggregates and ensuring adequate durability of reinforced concrete infrastructures are major steps towards sustainability. Performance-based Service Life Design and recycled aggregate concrete are intense research fields. Considering the research maturity of each subject on its own, it is time to couple them and deliver knowledge on performance-based Service Life Design for reinforced concrete structures incorporating recycled aggregates. This Special Issue of Materials International constitutes a way to disseminate results and findings from original studies, experimental programs, empirical, analytical and numerical modelling of initiation period (carbonation- and chloride ion-related), propagation period or both (service life). Probabilistic, semi-probabilistic and deterministic approaches are welcome.

Study on Recycled Aggregate Concrete Frame Joints with Method of Nonlinear Finite Element

2009 ◽  
Vol 417-418 ◽  
pp. 745-748
Author(s):  
Jian Zhuang Xiao ◽  
M.M. Tawana ◽  
Xiao Hui Zhu
Keyword(s):  
Finite Element ◽  
Seismic Behavior ◽  
Low Frequency ◽  
Nonlinear Finite Element ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Displacement Curve ◽  
Element Analysis ◽  
Aggregate Concrete ◽  
Concrete Frame

With the achievements made in the research of mechanical properties for recycled aggregate concrete, this paper adopts the method of nonlinear finite element to analyze the seismic behavior of frame joints. The frame joints are made of recycled aggregate concrete. It also takes into account the bond behavior between steel bars and recycled aggregate concrete in the core area of the joints, and the force-displacement curve of the joints is calculated. Nonlinear finite element analysis shows that the results of the calculations are in accordance with the test results. It is concluded in this paper that, built models with nonlinear finite element method can be applied in simulating exactly the same seismic behavior of frame joints under low frequency reversed lateral loading.

scholarly journals Analysis on Mechanical Properties of Recycled Aggregate Concrete Members after Exposure to High Temperatures

2019 ◽  
Vol 9 (10) ◽  
pp. 2057 ◽  
Author(s):  
Zongping Chen ◽  
Ji Zhou ◽  
Peihuan Ye ◽  
Ying Liang
Keyword(s):  
Mechanical Properties ◽  
Energy Dissipation ◽  
Bearing Capacity ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Displacement Ductility ◽  
Energy Dissipation Capacity

In order to study the mechanical properties of recycled aggregate concrete (RAC) specimens after exposure to high temperatures, 120 RAC prism specimens, 57 reinforced recycled aggregate concrete (RRAC) specimens, and 56 steel reinforced recycled aggregate concrete (SRRAC) specimens were designed, involving two varying parameters such as recycled coarse aggregate (RCA) replacement percentage and temperature. The performance degradation of RCA materials, RRAC members, and SRRAC members after exposure to high temperatures was analyzed in depth. The research results show that after exposure to high temperatures the surface color of members may change from cinereous to gray-white. Some cracks may appear on surface of members and the mass of members may be lighter. With the increase of the experiencing temperatures, the bearing capacity (compressive, bending, and shearing) of RAC and its members are reduced, but their ductility and energy dissipation capacity have little effect on the change of high temperature. With the increase of the RCA replacement percentage, the mass loss ratio, ultimate bearing capacity, and peak deformation of each RAC and its members increase slightly, and the displacement ductility and energy dissipation capacity of the RRAC members decrease slightly. With the increase in replacement percentage of RCA, mechanical properties of RAC and their members have little effect after exposure to elevated temperatures, and the fluctuation range is within 20%.

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