Study On The Application Of Waste Foundry Sand In Cement Stabilized Base

In recent years,with the rapid development of infrastructure construction,the production of waste foundry sand is increasing day by day.A large number of landfill not only lost the valuable resources in waste foundry sand,but also occupied a large amount of arable land.The waste foundry sand will cause pollution and destruction surrounding soil and water environment.At the same time,the road construction has developed rapidly and construction materials have been extensively excavated,as a result,resources are becoming scarce.Therefore,the development of new materials to replace the original material for cement stabilized base has a good environmental benefits,economic benefits and social benefits.Firstly,the physical and chemical properties of waste foundry sand were analyzed.The physical indexes such as particle size distribution,apparent density,water content and fineness modulus were measured.Based on XRD ray scanning and Jade software,the chemical composition of waste foundry sand was analyzed and the content of metal components in waste foundry sand was studied.Determine whether the content meets national requirements.Secondly,taking cement stabilized base as the research object,the mechanical properties and durability of cement stabilized base mixed with waste foundry sand were discussed.There are five replacement rate of waste foundry sand were selected:0%,5%,10%,15%,20%,three cement dosage were choosed: 3%,4%,5%.Through the compaction test,unconfined compressive strength test,splitting tensile strength test,resilient modulus test,freeze-thaw cycle test and dry-shrinkage test,the effect of cement dosage and replacement ratio of waste foundry sand on the strength index and durability of cement stabilized base was studied.Then,make sure the optimal cement dose and optimal replacement ratio of waste foundry sand.The results show that the addition of waste foundry sand has adverse effects on the cement stabilized base.However,when the cement dosage is 3% or 4%,and the replacement ratio of waste foundry sand shall not exceed 15%,the compressive strength,splitting tensile strength and resilient modulus meet the requirements of mechanical properties.At the same time,the durability is good and the dry shrinkage can meet the requirements when the cement dosage is 4%,the replacement ratio of waste foundry sand is not more than 15%.According to the road performance and economic cost,the best cement dosage is 4%,and the best replacement ratio of waste foundry sand is 15%.According to the experimental results,test road was paved.And make the 7-day compressive strength and splitting tensile strength as construction inspection index.Finally,the test results meet the requirements.