Research On Design Method Of Super Large Size Mixture

In recent years, with the increase of traffic load and tire pressure, premature rutting of heavy duty asphalt pavement has become the primary problem. Many asphalt technologists believe that the use of appropriately increase aggregate size will minimize or eliminate the rutting of duty pavements, and other performance won't reduce. Referring to the research result in foreign countries, the structure and performance of super large size mixture(SLSM),which the maximum nominal size of aggregate no less than 37.5mm,have been researched.In this paper, the composition and intensity mechanism of asphalt mixture have been analysed,and proposed the Marshall design method for super large size mixture.The volume characteristic, mechanical strength propertie, pavement performance, construction technology and the technical economic analysis of SLSM have been studied systematically.In the end the optimized design method of SLSM based on different structure demands was proposed.The results indicated that the grading of super large size mixture is discussed in this dissertation based on the theory of CAVF; The analytical results of forming methods showed that different forming methods for super large size mixture had important influnence on the volume parameter;Based on discrete element method,the research showed that aggregate size had a significant effect on the strength of super large size mixture,and with the increase of aggregate size the carrying path became more clear. The test results of pavement performance showed that The high temperature rutting resistance performance obtains the further enhancement is better than large stone asphalt mixture, but the low temperature crack resistance and the water stability is not very different; By the technical and economic evaluation,compared with common large stone asphalt mixture the cost of super large size mixture was low.Meanwhile, in this dissertation It had been proved that it is a feasible method to quantitatively evaluate the gradation of large stone asphalt mixture by using fractal theory that can determine the relationship between fractal dimension of SLSM and volume parameters;...