Bond-slip Constitutive Relation Between SFNMRC And Rebar

Steel fiber and nano-meter materials reinforced concrete(SFNMRC), which mix with steel fibres, nano-meter Si O2 and nano-meter Ca CO3 into concrete, is a new kind of composite materials. SFNMRC has both advantages of steel fiber reinforced concrete and the nano-meter materials renforced concrete. The mechanical properties and the bonding performance between SFNMRC and rebar were investigared and are as follows:(1)Through the experiments on 84 of 150mm×150mm×150mm and 30 of 150mm×150mm× 400 mm SFNMRC speciments, the effects of concrete grade, steel fiber volume rate, content of nano-Si O2 and nano-Ca CO3 on cubic compressive, spliting and flexure strength of SFNRC were investigated. The results show that the compressive strength increased by the increase of nano-Si O2 and nano-Ca CO3 content; the most effective amount of nano-Si O2 is 0.5% in 0%~2% for spliting and flexure strength of SFNMRC speciments; the spliting and flexure strength of SFNMRC speciments increased by the increase of nano-Ca CO3 content.(2)Through the experiments on 42 of Losberg bonding and 30 of Center bonding speciments, the effects of concrete grade, steel fiber volume rate, content of nano-Si O2 and nano-Ca CO3 on the bonding performance between SFNMRC and rebar were investigated. The results show that the most effective amount of nano-Si O2 is 0.5%~1% for bonding performance; the effect of nano-Ca CO3 on the bonding performance increased by the increase of nano-Ca CO3 content. Through the analysis of test results, a calculation method of bond strength considering the effect of steel fiber volume ratio on bond-slip curve feature point was proposed. As a result, the bond-slip constitutive relation between SFNMRC and rebar under different steel fiber volume ratio was proposed.