Uses Of Quarry Waste In Highway Construction And Optimization Of Pavement Structure

Gravel material is not only an indispensable material of highway engineering,but also a nonrenewable mineral resources. In recent year, newly-increased mileage of road is 100,000 km in China every year. Those engineerings drain billions of tons of gravel materials,which hurts natural landscape and ecological environment of origin. Moreove, it brings about 400 million tons of quarry waste,because of low productivity of quarry.Uses of them is a technical problem of highway engineering and a problem of ecological environment. This paper is an example.The route of Jiekou extension of Zengcong highway in Guangdong Province is across qurry waste area of Rongxing Quarry in Conghua Districe of Guangzhou City,which is K17 +080 to K17+620. This area inside land expropriation's line is 32,000 m2 ,in which there are about 600,000 m3 quarry waste. Because of their relative abundance, the issues of address- ing,environment,time and expense of transportation are hard to handle. This paper discusses the feasibility of uses of quarry waste in subgrade and pavement structure and the problem of transportation and use, so as to use the wastes economically and availably.In this paper, we study the material's roperties of quarry wastes, the feasibility and practical engineering used in highway and optimization of asphalt pavement structure. In the field of material, analyze grain size,physical property and the feasibility of the waste usde in highway, base on a large number of tests. The results show that quarry wastes could be used in road bed and cement stabilized soil subbase. In the part of road bed, test the maximum dry density of the waste under various factors and study the construction parameters and quality control indexes base on the test road. Moreover, we study indoor and outdoor's modulus of resilience of the waste, in order to provide a credible index for optimize structure. In the part of cement stabilized soil subbase, the performances indexes are studied through indoor tests,test road and inspection of construction. In the field of optimization of pavement, calculate optimization results of pavement base and asphalt surface layer with BISAR sofeware and its economic profits.The results show that, the variation coefficient of physical property of quarry waste is small, except grain size and plasticity index. This material could be used in road bed and cement stabilized soil subbase. Its biggest dry density is influenced by many factors. Construction's quality of road bed coule be controlled well under compaction degree and settlement index. As a consequence, modulus of resilience could advance 70%,while pavement settlement and tensile stress of bottom could be reduced effectly. Pavement performance indexes of cement stabilized soil subbase fit specifications. The thickness of base course could cut down 6cm under the answer of analysis. It brings a considerable economic profits and society's influence.