Study On The Punching Performance Of Two-Way Concrete Slabs Strengthened With CFRP Laminates

Carbon fiber reinforced polymer(CFRP)is a new type material used in civil engineering. Because of its many advantages, such as lightweight, high strength, perfect corrosion resistance, especially construction convenience and little modification of physical dimension of structures, CFRP is widely used to strengthen buildings. Though RC slabs is important structure members in common use, study on the performance of RC slabs strengthened with CFRP is very few and furthermore study on the punching performance of two-way RC slabs strengthened with CFRP is fewer.In this paper, the experiment study on the punching performance of two-way RC slabs stock on bottom surface with CFRP laminates is introduced. The destructive experiment of two group members stock with CFRP laminates in three different ways have been finished. The ultimate load, the failure form, the deformation and crack characteristics are studied, the peeling phenomenon of CFRP laminates is also described. It is indicated in the experiment that the punching bearing capacity and the stiffness of the two-way RC slabs strengthened with CFRP laminates are improved, and it is clear that the strengthening effect is affected by strengthening ways.According to the punching theories of the common RC slabs and the researching productions of the concrete members strengthened with CFRP, the calculating method of the punching bearing capacity of RC slabs strengthened with CFRP laminates, which is validated by the experiment, is brought forward. The results indicate that the plastic angle method of the common RC slabs can also be applied to calculate the punching bearing capacity of RC slabs strengthened with CFRP, but the angle should been corrected when the ultimate bending moment is calculated. Based on the theory analysis and the experiment results the corrected calculate method is proposed and then the design method is also proposed as reference of practice engineering.