Experimental Study On Road Performance Of Recycled Brick Concrete Aggregate Used In Asphalt Stabilized Macadam

In recent years,large-scale urbanization has led to a large number of construction and demolition wastes,how to solve a series of practical problems such as waste occupying land,polluting the environment and affecting the city’s appearance is an urgent problem.The construction and demolition waste is used as the recycled aggregate in the asphalt stabilized macadam base layer of the highway,and the waste recycling is realized to the greatest extent,which not only solves the practical problems brought by the waste but also saves the natural aggregate.The regeneration researched in the article Aggregates are mainly waste concrete and waste bricks in construction and demolition waste.In order to understand in detail the road performance of recycled aggregates used in highway asphalt stabilized macadam base,this paper studies the road performance of recycled asphalt mixture under different brick aggregate ratios of different recycled aggregates.First,review relevant literature and field research at home and abroad,and formulate technical routes based on the research content of this paper,detailing the processing flow of recycled aggregates,in order to more intuitively understand the formation process of recycled aggregates.According to the "Highway Aggregate Test Procedure JTG E42-2005",the basic physical performance indexes of the recycled aggregates were determined,which prepared for the subsequent application in the asphalt mixture.Secondly,according to the actual screening pass rate of the recycled aggregate,the Bailey method was used to design and verify the gradation of the mixture,and the proportion of each grade was 33.3%:24%:12.3%:26%:4.4%,it is estimated that the amount of asphalt is 3.8%,and the basic performance indexes such as stability,flow value,void ratio and density of the recycled asphalt mixture are obtained by Marshall test in five ratios of 3.5%,3.8%,4.1%,4.4%and 4.7%,according to each index,the best oil-stone ratio corresponding to the recycled asphalt mixture is obtained,and the following is prepared for the research on the road performance of the recycled asphalt mixture.Finally,in the case of the optimum oil-stone ratio corresponding to the recycled asphalt mixture,through uniaxial compression test,splitting tensile test,water immersion Marshall test,freeze-thaw split test,hamburg rutting test to determine the mechanical properties,water stability performance,high temperature stability and other road performance of recycled asphalt mixture,the results show:when the proportion of brick concrete is 0:10、2:8、4:6、6:4 four conditions,as the recycled aggregate increases from 0%to 100%,the corresponding compressive strength,rebound modulus,and splitting tensile strength are all reduced;residual stability,freeze-thaw splitting strength are reduced;the dynamic stability increases and reduced rut depth.