TORSIONAL BEHAVIOUR AND STRENGTH CALCULATION METHODS OF ANGLE STEEL REINFORCED CONCRETE BEAMS

In order to study the pure torsional properties of angle steel reinforced concrete beam (ASRCB),7 specimens were designed,and three parameters were considered in the test,which are steel disposition forms,steel protective layer thickness and concrete strength grade. The failure patterns were observed,the curves of the whole force process,the cracking torque and the ultimate torque were obtained,and the influence of the three parameters was analyzed. The experiment results show that: the failure pattern of ASRCB under pure torsional load is the yielding of angle steel with concrete in the corner crushed,and ASRCB has better torsional properties. The increase of the volumetric percentage of steel and the concrete strength grade can improve the torsional properties effectively. The increase of steel protective layer thickness may weaken the torsional properties. Based on the experiment results,the strength formula of ASRCB under pure torsional load was proposed. Calculated results coincided with the test results. These results may provide reference for further research on steel concrete composite structures.