Mechanical behavior and bearing capacity calculation of steel reinforced recycled concrete beam after experiencing high temperature
Chen Zongping1, 2, Zheng Wei1, Chen Yuliang1
1. College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, China; 2.Key Laboratory of Disaster Prevention and Structural Safty of the Ministry of Education, Nanning 530004, China
Abstract：In order to study the mechanical behavior of steel reinforced recycled concrete beams after experiencing high temperature, thirty-two specimens, involving three varying parameters such as temperature, recycled coarse aggregate replacement ratio and shear span ratio, were designed for monotonic static loading test after experiencing high temperature. Based on the tests, the appearance change and mechanical failure pattern of specimens after experiencing high temperature were observed, so that those important information including load-deflection curves, cross-sectional stress distribution and ultimate bearing capacity of the specimens can be obtained. Furthermore, the effects of these varying parameters on the mechanical behavior of steel reinforced recycled concrete beam after experiencing high temperature were analyzed, and the calculation method for the ultimate bearing capacity of steel reinforced recycled concrete beam was also discussed. The research results show that the failure mode of steel reinforced recycled concrete beam after experiencing high temperature is similar to that at the normal temperature, but after experiencing high temperature the surface color of beam may change from gray to dark yellow and some cracks may appear on the beam surface. Additionally, due to the high temperature, the ultimate bearing capacity and stiffness of beam decrease, and its ductility degenerates. The replacement ratio of coarse aggregate has little effect on the bearing capacity and stiffness of the specimens, but it may significantly affect the ductility of beam. With the increase of shear span ratio, the bearing capacity and stiffness of the specimens descend, but their ductility becomes better.
