Experimental Study On Bending Fatigue Behavior Of RC Beams Strengthened By Stainless Steel Wires

A new structure rehabilitation technology of high-strength stainless steel wire mesh with permeable polymer mortar has been put into use in China. No research has been conducted on the subject of fatigue behavior of RC beams strengthened by this new technology up to now. So it is necessary and important to investigate the fatigue behaviors of RC beams strengthened by high-strength stainless steel wire mesh(HSSWM).In this thesis, 8 RC beams were tested under static load and repeated loading. The tests under static load, which include one compared beam and one beam strengthened by HSSWM, indicate that RC beams strengthened by HSSWM have higher capacities and higher stiffness and that theories about HSSWM method in previous literatures are reasonable. In the tests under fatigue loading, which include one compared beam without being strengthened and 5 RC beams strengthened by HSSWM, all the beams fail due to the fatigue of steel bars in the initial beams. The test results show that RC beams strengthened by HSSWM have longer fatigue life.In the analysis part, the followings are discussed: the relation between the concrete strain on the edge of compressive zone and the number of cycles, the relation between the tensile strain of the longitudinal steel bars and the number of cycles. Formulae are proposed to evaluate the fatigue life of the beams and to calculate the stiffness of cross-section under certain number of cycles. A criterion to avoid fatigue failure of RC beams strengthened by HSSWM is also proposed in the thesis.This thesis forms a part of the serial researches of high-strength stainless steel wire mesh strengthening method (HSSWM method), providing basic theories and conclusions for rehabilitation design and further research.