Experimental Study On Steel Reinforced Concrete Torsional Members

In order to study the torsional performance of the Steel Reinforcement Concrete (SRC) member, it was studied form 4 SRC specimens and 2 RC comparision specimens sustain torque moment. 4 groups comparision specimens can be makeup with the major parameters of the stirrup contents,the longitudinal steel bar contents and the formed steel contents. The experiment adopted the mechanical modle that one end is fixed, the other end is free, and the speimens sustain the monotone static stepped load, and the torque moment symmetrically exerted at the loading beam of the free end by 2 instep lifting jacks.The crack developing modality, the wreck modality and torsional deflection rule of RC and SRC specimens was narrated and analyzed. Through the test of SRC and RC comparision specimens, the infection of the stirrup contents,the longitudinal steel bar contents, the formed steel and the formed steel contents to torsional performance was analyzed and demonstrated.Through analyzing the test date indicated that: It is feasible to calculate the craze torque moment of SRC member according to the RC member, and the benefition of the steel bar and formed steel to resist crack can be neglected; The formed steel can remarkably increase the torsional bearing capacity and late stage torsional stiffness of the member, and remarkably improve it's ductility; The torsional bearing capacity of the SRC member can be obviously improveded by increasing the stirrup quantity; The torsional capacity of the SRC member can be effectively improveded by increasing the longitudinal steel bar contents and the formed steel contents, but the effectiveness is less significant than increasing the stirrup contents.Lastly, this paper discussed the calculation formula of torsional craze torque and torsional capacity of the SRC member, and preliminary advice that the craze torque moment of SRC member can be calculated according to the RC member, and the benefition of the steel bar and formed steel to resist crack can be neglected; The torsional bearing capacity of the SRC member makeup by the RC part and SRC part, the contribution to torsional bearing capacity owing to the interaction between the formed steel and concrete can be expressed by the bearing capacity augmenting factorγ₁, the formula (5.18) can reflected the actual torsional bearing capacity bacically, and it's physical significance is clear, can be consulted for further resaerch or correlation norm.