Asbestos Tailings Asphalt Concrete Pilot Study

This paper taked west transportation construction science and technology project Study on Technology of Asbestos Tailing Used as Pavement Construction Materials (200731800003) of ministry of communications as background, and studied to use asbestos tailing, which has been stacked near Yaan-Lugu highway from K112 to K145 mileage for more than 30 years, as asphalt mixture aggregate for pavement. It had the important project practice significance and the theory research value.We did the systematical study about physical and chemical properties of the asbestos tailing, aggregate characters and performance of asbestos tailing used as asphalt mixture aggregate, by means of field investigation,indoor experiments,theory analysis, etc. The main work and summaries concluded are as follows:(1) Mineral and chemical composition of asbestos tailing is determined, toxicity examination of asbestos tailing and PH experiment of the soil in the accumulation area are carried out. The results show that asbestos tailing is non-toxic and the soil is non-polluted.(2) The basic performance of asbestos tailing can meet required criteria when used as aggregate in the middle and lower layer of asphalt mixture. At the same time, other experiments on the fundamental characters as the raw material were done, they also satisfy with the required technical norms.(3) The gradation of asbestos tailing and asphalt mixture was designed, The determined type of gradation is that AC-20C is applied to the middle layer, AC-25C is applied to the lower layer, and separately the best ratio is 4.4% and 3.9%.(4) It is included that asbestos tailing has good high temperature stability, low temperature stability, water stability and permeability of water capacity, through testing the performance and studying the mechanism of asbestos tailing and asphalt mixture. And asbestos tailing is cube-shaped particles, rough superficial texture, alkaline and contains some short and small asbestos fibers, etc. These characters play remarkable role to make asbestos tailing and asphalt mixture show good pavement performance.