Experimental Study And Nonlinear Numerical Simulation On Bond Behavior Of Reinforcing Steel And Machine-made Sand Concrete

Machine-made-sand is particles made by the river gravel or broken rock aftermechanical crushing and sieve,whose size is less than4.75mm. Machine-made sandproduced by the local rocks or pebbles,instead of natural sand, has been widely usedin particular application.Machine-made-sand have irregular multi-angular shapes andthe particle size distribution is worse than natural sands under the same finenessmodulus.Machine-made-sand used in the concrete would have differences betweenthe concrete made by the natural sands in some aspires,such as mix,work performance,mechanical and durability.The effect of machine-made sand on bond behavior ofconcrete and rebar are researched in this article. Further more,the bond behavior isnumerical simulation by ANSYS on bond mechanism.This article’s primary researchis as follows:1.Pull out specimens with MSC and plain bars were made for studying bondbehaviors.Compared with the natural sand concrete,MSC and plain bar has nosignificant differences.The bond behavior is influenced by many factors,such ascomposition of concrete,the relative bond length between concrete and bars,concretestrength,surface of the bars and so on.2.Pull out specimens with MSC and ribbed bars were made and tested.Theresults show that the bond behavior of MSC and ribbed bar is better than the naturalsand concrete.When concrete strength grade is C50,bond strength shows a slightdecline with stone powder content increases,however the holistic bond strength is stillhigh.3.Based on the above tests,three-dimensional finite element model wasestablished by ANSYS for analysis and calculate. Firstly,Spring element was used inthe three-dimensional finite element model for simulating bond-slip relationship curve,Calculation results were well fits with the experimental results.Then local finiteelement model was established by the area-area contact elements for themico-simulation of bond mechanism.