Experiment on the Pure Torsional Performance of Geopolymer Concrete Members
In order to investigate the torsional performance of geopolymer concrete members,and discuss the application of existing codes for design of concrete structures to geopolymer concrete members.The investigated parameters include stirrup ratio(0.42%and 0.99%),and longitudinal reinforcement ratio(0.65%and 1.17%).A total of 3 test members were designed.Through the test,the failure modes and crack propagation were observed,the torque-angle of twist curves,torque-reinforcement strain curves and torque-concrete strain curves of the members were recorded,and the influence of various parameters on the torsional performance of geopolymer concrete members was investigated.The failure modes of geopolymer concrete members closely resemble that of ordinal concrete members,which are under-reinforced failure,suitably reinforced failure and partially over-reinforced failure.The ultimate torque of geopolymer concrete members essentially increases with the increase of stirrup ratio and longitudinal reinforcement ratio.The main crack inclination angles of members decrease as the reinforcement strength ratio increases.The results show that increasing the reinforcement ratio of members can improve the torsional bearing capacity of geopolymer members obviously.Code for design of concrete structures(GB50010-2010)can predict the ultimate torque of geopolymer concrete members well.The mean value and coefficient of variation of the ratio between the predicted value and experimental value are 0.92 and 13.6%.
pure-torsional behaviorgeopolymer concretefailure modeangle of twist