The Application Of Large Stone Asphalt Mixture In Expressway Reconstruction And Expansion Project

At present, the large stone asphalt stabilized macadam pavement has been used in the reconstruction and extension of expressway. But the study of the material and structural properties are imperfect, what’s worse, living parameters, performance and related information are lacking. It is very important to supplement and improve the information, which has realistic meanings to research large size asphalt mixture systematically, solve the problem of road asphalt roadbed diseases and improve the quality of highway design and construction of the reconstruction.Based on Jing-tai Expressway Hefei-Xuzhou south section project, this article analyzed the disease of semi-rigid asphalt pavement and the damage characteristics compared the effect of different restoration measures. By the contrastive analysis of the deflection, subgrade modulus, unconfined compressive strength and dynamic modulus between large stone asphalt mixture repair method and other traditional methods, the results show that, the deflection of large stone asphalt mixture repaired section is smaller, the load-bearing capacity of the structure is more uniform, and the service life of pavement structure is longer.Based on Jing-tai highway Xichong to Fangxing Avenue extension conditions, this paper researched the typical structure of the old road rebuilding, which consisted with Anhui Province material characteristics, climatic and the traffic conditions. We have collected the mechanical response and temperature change conditions of the pavement structure under traffic load by embedding the stress, the strain and temperature sensor in the large stone asphalt pavement structure, which can provide the basis for mechanical properties tests and theoretical calculation, and establish the data evaluation basics for long-term observation of performance. In the construction process or before opening traffic, we have done a lot of testing, such as the subgrade bearing capacity test, the thickness of pavement structure, rutting test, deflection, flatness, lateral force coefficient and structure depth and so on. The strain response of asphalt layer bottom had been measured under the condition of the standard axle load10t and overload axle load18t. The results show that the asphalt layer bottom strain can meet the requirements of limit strain design index.