Experimental Study On Flexural Properties Of Layer Type Hybrid-steel Fiber Reinforced High Strength Recycled Concrete Beams

This essay will argue that the benefits of using recycled aggregate instead of nature aggregate and part of cement replaced by silica fume and fly ash.The purpose of this method is that recycle construction waste and industrial waste.As a result of the recycled concrete birth defects,it will lead to low strength of concrete.Therefore,the experimenters add steel fiber into the recycled concrete during the experiments.In order to reduce total dosage of steel fiber,experiments adopt layered method and distribute hybrid steel fiber which is mixing by two different shapes of hybrid steel fiber in the tension zone of beam in a reasonable way.This method could maximize the effect of steel fiber.Furthermore,the bending capacity of the test beam is divided into two parts.The first part is only change the total mixing steel fiber in concrete mixing ratio.The purpose is analyzing the change of the hybrid steel fiber mixing rate of high strength recycled concrete compressive strength,tensile and the impacts of elasticity of modulus.In addition,it could test hybrid steel fiber mixed rate changes on the bending properties of high strength recycled concrete beams.According to the analysis of test results,recycled concrete and beam components have the best performance when the hybrid steel fiber mixing rate at 1.0%.Therefore,taking 1.0%of total hybrid steel fiber mixing rate during the layered experiments.During the second part of experiments,experimenters added hybrid steel fiber on the bottom of the strong recycled concrete beams which is the reference beam.The depth of section of beams are divided into six parts equally.The height of steel fiber reinforced concrete is 1/6H,2/6H,3/6H,4/6H,5/6H and H respectively.In the layered of beams experimental groups,the steel fiber reinforced concrete's bending has the best performance when the height is 3/6H and 4/6H.After checking test results and analyzing it,this essay also amend the actual situation of mixed layer steel fiber which refers to the calculation formula of normal section flexural capacity of?Technical Specification for Concrete Structures of High Strength?and also combines with?Technical Specification for Concrete Structures of Fiber?.We compare the calculated value and experimental value and also put forward a correction coefficient which refers to the calculation formula of hybrid steel fiber recycled concrete beams.There is better fitting effect obtained.Meanwhile,experimenters did a nonlinear simulation analysis for layers of mixed flexural performance of steel fiber reinforced high strength recycled concrete beams by using finite element software ANSYS.The result is equal to theoretical calculation value.