Influencing Factors Of Asphalt Mixture Hign Temperature Performance And Its Improving Measures Based On Shear Resistance Strength

Asphalt pavement is mainly composed of asphalt mixture, the high temperature performance of which is directly connected with the high temperature rutting resistance of asphalt pavement. A large number of surveys and experimental studies showed that rutting was caused by shortage of shear resistant strength. The issue that how to improve the high temperature of asphalt mixture according to shear strength parameters has not yet formed a consensus currently, some one believes that the high temperature performance of asphalt or asphalt mortar should be improved in order to increase the shear strength of asphalt mixture; others believe that the performance of aggregate or gradation should be improved in order to increase the shear strength of asphalt mixtures. Therefore, there is no reasonable and uniform guidelines during the asphalt mixture design procedure, which resulted that how to improve the asphalt mixture at high temperature shear strength is still in chaos.Aimed at the controversy exited in the high temperature shear strength of asphalt mixture, this paper based on the diagnosis of asphalt pavement rutting causeses, make clearly the the influence of shear strength on the high temperature performance of asphalt mixture, select the simple test method, analyze the influence factors and their influence degree of the strength parameters on the high temperature performance of asphalt mixture. According to this analysis, this paper select the anti-rut agent as the effective measure to solve the problem of asphalt pavement rutting, analyze the modify mechanism of anti-rut agent and its effect of asphalt mixture high temperature performance, and then provide the optimal dosage of anti-rut agent.In this paper, the causes and the mechanism of rutting were analyzed, and the effects of material properties, aggregate gradation, mortar and strength parameters of asphalt mixture on rutting performance were researched, which based on actual research. The results show that the rutting deformation of asphalt mixture is mainly about the shear flow deformation, it mainly caused by the low shear strength, and the effects of strength parameters of asphalt mixture on the temperature performance of asphalt pavement is significant.Secondly, according to research at home and abroad, the indirect tensile test and unconfined compression test method was used to determine the asphalt mixture shear strength parameters—cohesion C and the friction angleφ, which combined with asphalt mixture rutting test, analyzed the connection between shear strength parameters and the high temperature properties of asphalt mixture, and used the gray correlation analysis method to qualitatively analyze the influence degree of shear strength to the high temperature properties. The results show good correlation about the shear strength parameters of asphalt mixture with rutting. For high temperature performance of asphalt mixtures, the importance of cohesive force C is the top, but the influence of friction angle cp is not negligible at the same time..Then, anti-rut agent was taken as the effective technological improvement measure to high temperature performance of asphalt mixture, the modification mechanism of anti-rut agent was analyzed, and the influence factor about high temperature performance of anti-rut agent modified asphalt mixture was researched. And investigated with the economic benefit, the reasonable amount of range anti-rut agent was determined. Further proved the good high temperature rutting resistance of anti-rut agent modified asphalt mixture, according to the structural finite element analysis. Proved by test road of Qiancao hiway, anti-rut agent modified asphalt pavement achieved excellent performance, which provided reliable and valuable experience for the prevention of asphalt pavement rutting under overload and high temperature.