Experimental Research On The Bond Performance Between Carbon Fiber Reinforced Plastic Bars And Reactive Powder Concrete

Concrete reinforced with steel reinforcing bars has been used successfully in civil engineering for decades. However, the corrosion of these structures, particularly when they are located in such aggressive environments as coastal and marine structures, is serious. As an alternative to steel reinforcing bars, carbon fiber reinforced plastic bars (CFRP bars) has the advantages of excellent corrosion resistance and mechanical properties. Reactive powder concrete (RPC) is a ultra-high performance concrete with excellent durability and mechanical performance which is invented by Pierre Richard in 1990s. And it is assumed that the combination use of CFRP bars and RPC can greatly improve the serviceability of structure. The precondition of the combination is the bond performance between two materials. Thus, the main object of this article is to conduct an experimental research on the bond performance between CFRP bars and RPC, so as to provide referenced data for the combination use of them.Through direct pullout test, we examine the effect of the water to cement ratio, contend of steel fiber and silica fume on the bond behavior; compare the bond behavior of two types of CFRP bars with difference surface treatment (R1 bars and G1 bars), and reprocess the one of inferior bond strength; investigate the bond stress distribution along the bond length of CFRP bars, and assess the adequacy of some exist analytical models of bond-slip behavior to reproduce the experimental bond behavior. The conclusions are as follows:(1) The compose of RPC has an effect on the bond behavior between CFRP bars and RPC: the bond strength between CFRP bars and RPC will increase with the decrease of water to cement ratio, but doesn't obviously; the adding of steel fiber can improve the bond behavior between CFRP bars and RPC significantly, but steel fiber will also effect the workability of RPC, consider the bond behavior and economy, the content of steel fiber should be 2%;. silica fume can improve the bond strength between CFRP bar and RPC, but the bond strength isn't in proportion to the content of silica fume, in this experiment, the optimal content of silica fume is 0.25 to 0.35.