Study On Pavement Performance Of Construction Waste Recycled Aggregate

As urbanization continues to accelerate in Guangzhou,emissions of the urban construction waste are growing rapidly, and which has exceeded disposal of construction wastes in Guangzhou.Such a large amount of construction waste treatment problems have restricted construction progress of urbanization.Construction wastes which use to road base and cushion that their strength demand are relatively low, improve urban construction waste utilization and implementation of building waste resources, and help to solve the problems of land resource occupancy and environmental protection.At present, Our country lack specifications and a large number of systematic study on construction waste recycled aggregate in the standardization of the roadbed and pavement engineering. For pavement performance of construction waste recycled aggregate application in base, the article launched a series of related research work.First the article analyzes characteristic of construction waste recycled aggregates, and through a lot of systematic experimental study on its basic performance.Studies have shown that construction waste recycled aggregate is characterized by the hardening of surface coated with cement mortar and internal micro-cracks, these factors leading to compared with natural aggregates, the recycled aggregate's density is lower,its water absorption is higher, and crushing value is higher.Brick have poor performance, and with the content of brick increases,the basic properties of recycled aggregate of brick and concrete decreases.Then, according to the characteristics of construction waste recycled aggregates,we use graded dense framework structure.and on the basis of that, study on mechanical properties of recycled aggregate is getting on, which is 7 day unconfined compressive strength test.Research shows that above 3% and 5% cement content of recycled aggregate concrete cement-stabilized materials can respectively satisfy the specification's strength requirements of the severe heavy traffic of Highway subbase and base.Replacing recycled fine materialwith natural fine material that improve the mechanical properties of cement stabilized recycled aggregates.In order to ensure road base requirements for mechanical property of road base of norms, brick aggregate content in the recycled aggregate should be controlled in the range 5% or increasing the cement dosage accordingly.Secondly, the article study and analyzes the mechanism of drying shrinkage of cement stabilized macadam based.Base on the properties and mix design of recycled aggregate, we launch shrinkage tests, and determine the shrinkage performance that cement-stabilized material of concrete and brick and concrete recycled aggregate.Studies show that the cement content, age and loss of water influence the shrinkage coefficient of recycled aggregate cement stabilization materials;Brick is prone to drying shrinkage of cement stabilized recycled materials in early stage.Finally, combine with results of laboratory test, we carry out the project of Guangming high-speed test section and road base of Zhoutouzui tunnel.The testing situation reflects the project works well, construction waste recycled aggregate which applyed to pavement base and subbase,has very good prospects.