Experimental investigation on static flexural behavior of fatigue damaged SRC beams strengthened with CFRP sheets

This paper presents an experimental investigation on CFRP strengthening of severely fatigue damaged SRC (steel-reinforced concrete) beams. Bending tests were carried out on three types of SRC beams: (1) SRC beams without any damage, (2) damaged SRC beams repaired by welding and (3) damaged SRC beams repaired by welding and CFRP. Failure modes of different types of SRC beams were compared. The effects of fatigue loading history and CFRP on static performance of SRC beams were studied. The experimental results showed that, for the fatigue damaged SRC beams, flexural bearing capacity can be restored if they were repaired by welding fractured beams and re-bars even without CFRP sheets, but the plastic strengthening of encased steel is weakened. CFRP sheets can effectively increase the ultimate flexural bearing capacity and overall stiffness of SRC beams. Meanwhile, it can delay crack propagation, reduce the width of surface cracks, and decrease the deflection under yield load and ultimate load. Finally, the strength of CFRP sheets will be fully utilized by using end anchorages.