Analytical model for the torsional response of steel fiber reinforced concrete members under pure torsion

Rausch space truss theory (1925) is the earliest theory to predict the torsional response of RC members subjected to pure torsion. Softened truss theory proposed by Hsu considering the softening effect of concrete fairly estimates the torsional strength of the members under pure torsion. These theories consider the member to be a cracked one, so that the truss action activates. This assumption reduces the initial torsional stiffness of the cross-section. However the model proposed by Hsu considering the softening effect of concrete fairly estimates the ultimate torque carrying capacity of the RC member. Fiber reinforced concrete is a better option in the construction of blast resistant and earthquake resistant structures. Relatively little research has been reported on the analytical studies of SFRC members subjected to pure torsion. Thus in this paper an attempt has been made to develop an analytical model for predicting the torque-twist response of SFRC members subjected to pure torsional loads considering the softening effect of concrete. Experimental validation was also presented in this paper.