Study On Mineral And Chemical Composition Of Limestone And Its Application In Asphalt Pavement Structure

Because of their different deposition area, formation causes and conditions, the mineral containing components and so on, different kinds of limestone exist in earth’s crust. According to the different chemical composition of the mineral, limestone can be classified into dolomitic limestone, siliceous limestone, clayey limestone and so on. The technical characteristics of aggregates of strength, crushing value, abrasion value, the value of polish are also different for various kinds of limestone. Aggregates are the major and important raw material of the pavement structure layer, each of the layer have various requirements of technical characteristics of the aggregates. Based on the "A Research on the Application of Limestone to the Anti—skidding Surface of Asphalt Pavement of Yunnan Province High Way", this thesis focuses on the relationship between limestone’s mineral composition, chemical composition and its technical characteristics and analyses the applicability of different lithologies of limestone aggregates in asphalt pavement layer.The limestone in8quarries along the Yunnan province Longrui highway is selected to conduct research in the paper. X-ray diffraction, spectroscopy, laser particle size analyzer and other equipment are used to detect and analysis the limestone in the8quarries in terms of the mineral composition, chemical composition and particle morphology of aggregate. Through the test of various aggregates on the apparent relative density of the material, water adsorption, crushing value, abrasion value, the value of polish, compressive strength, soundness and adhesivity, and other qualifications. With the help of grey correlation theory and the analysis software of grey correlation theory, this thesis calculates the degree of the correlation between limestone’s mineral component and its technical characteristic. The research shows that the aggregates of8limestone quarry have different physical and mechanical properties, and these properties have connection with the mineral and chemical composition of the aggregate of limestone. The calcite in the mineral composition of limestone is closely related to aggregates’ technical characteristics, in other words, the content of calcite in the mineral composition mainly determines the physical and mechanical properties of the aggregates of limestone.According to the analysis and selection requirements of the asphalt pavement layer, it further analyses the applicability of limestone with different technical characteristics to the pavement structure layers. Rocks are selected from ShiWubiao and EnHe quarry for a test for anti-skidding performance on asphalt pavement, and it analyzes the road performance of different limestone through the test for high temperature stability, low temperature stability, water stability and sliding wear resistance test, it turned out that ShiWubiao quarry can be used to the anti-skidding surface of asphalt pavement.This thesis analyzes the different technical characteristics of its aggregates through the mineral composition and the chemical properties of limestone, and presents its applicability in asphalt pavement structure, the research results are of theoretical significance and practical value to select anti—skidding surface material and the analysis of the micro perspective of stone.