Application Of Recycled Lightweight Aggregate Concrete In Reinforced Concrete Beam

Recycled lightweight aggregate concrete is made of ceramic and brick based construction waste as coarse aggregate,and that can be mixed to a new type of special concrete.This concrete can not only reduce the pressure caused by the lack of modern high-quality aggregate,but also reduce the pollution of urban and rural construction waste to the environment,and reduce the weight of the building.In order to research the properties of recycled lightweight aggregate concrete in concrete member,ceramic,block and waste brick after treatment are as concrete aggregate,experiment is designed with a ordinary concrete beam LI and six recycled lightweight aggregate concrete beams L2~L7 to make a contrast of flexural performance by adjusting the mixture ratio.The main research work is as follows:(1)With reference to the stress-strain relation expression of ordinary concrete existing,combining with stress-strain curve of recycled lightweight aggregate concrete studying by research group,the stress-strain relationship expression of recycled lightweight aggregate concrete is regression fitted.It will provide some technical support for the later research on the strength,crack and deformation of lightweight aggregate concrete.(2)Through describing the process of bending test of L1 ~ L7,the test beams on the crack,development situation,numerical indicator and ultimate limit failure state are presented in detail.The flexural process of recycled lightweight aggregate concrete beam is similar to that of ordinary concrete beam,and it can be roughly divided into three stages: elastic working stage,crack working stage and limit failure stage.To carry out the crack distribution map of the test beam L3 in final failure for example,the process of crack distribution is summarized which is roughly divided into three stages: initial stage,crack full development stage and crack mutation stage.At the same time,combining the different material of each test beam,the difference of deflection and crack of 7 beams in bending is contrasted.(3)Based on the calculation formula of flexural capacity of ordinary concrete beams,combined with the experimental results,the relationship between the rectangular equivalent stress coefficient and the replacement rate of recycled coarse aggregate is exploratory fitted,and the linear relationship between the two is obtained,then the formula for calculating the flexural capacity of recycled lightweight aggregate concrete beam is obtained.Comparing the experimental results with the calculated values of the flexural capacity of recycled aggregate lightweight aggregate concrete beams,the results show that the formula of flexural capacity of regenerated lightweight aggregate concrete beams possesses a certain rationality.