Experimental Research On Splitting Tensile Properties And Seeping Behavior Between Steel Fiber Reinforced Concrete And Exiting Concrete

Through the experimental study, it is explored that bond splitting tensile properties between SFRC and exiting concrete,the bonding interface's antifreeze splitting tensile properties and seeping behavior. The main research works have been accomplished in this paper:1,Through the experiments on 81 bonding specimens between SFRC and existing concrete with the dimensions of 100mm×100mm×100mm and 30 bonding specimens of 150mm×150mm×150mm, the effects of steel fiber volume fractions and pouring methods on bond splitting tensile properties were studied, also the effects of size effect on the bond splitting tensile strength and the effects of fiber volume fractions on breakage deformation of the bonding specimens were studied. The calculating mode of the bond splitting tensile strength considering the impacting of fiber volume fractions,the old concrete's splitting tensile strength,roughness and adhesion agent was built. And the conversion coefficients about size effect was given.2,Through the experiments on 30 overall SFRC specimens with the dimensions of 100mm×100mm×400mm,120 overall SFRC specimens of 100mm×100mm×100mm and 105 bonding specimens between SFRC and existing concrete with the dimensions of 100mm×100mm×100mm, the impacting of steel fiber volume fractions and the numbers of freeze-thaw cycling on bond splitting tensile strength were investigated with the method of fast freezing and thawing test. The results show that after the incorporation of steel fiber, the frost resistance of the overall and bonding concrete are both improved significantly. At last, based the established mode, the calculating mode of the splitting tensile strength of the bonding interface is established further, which considers numbers of freeze-thaw cycle.3,According to the current impervious testing standard method in China, through the seeping behavior experiments of 36 overall concrete specimens and 30 bonding interface specimens between SFRC and existing concrete, we can know that after the incorporation of steel fiber the impermeability of the overall concrete increases slightly and the impermeability of the bonding interface is improved significantly; The permeability of bonding interface is much bigger than the new and old overall concrete. At last we discuss the percolation calculation model of the adhesive surface between SFRC and the old concrete.