Researching On High-temperature Shear Of Asphalt Mixture Pavement Under Heavy Duty Loading

Asphalt pavement is one of the primary structures for main roads in China.Along with the appearing and forming of the heavy-loaded traffic in recent years,the premature failure of asphalt pavements is becoming more and more widespread.Consequently,over loading has become one of the key factors which influence the pavement performance and shorten the pavement life. The serious traffic and over loading of vehicles result in higher shear stress in the pavement structure. The asphalt mixture shear capability is decreased under high temperature environment, thus rutting is serious, particularly at the channel traffic. So studying the shear strength of asphalt mixture under high-temperature seems to be urgent.The high-temperature shear studying of heavy-loaded asphalt pavement has been conducted on two aspects about semi-rigid asphalt pavement structure and material performance in this paper. On the one aspect, analyzing heavy-duty pavement structure by using BISAR, calculating maximum shearing stress of the structure layers under different load function, getting the shearing stress of asphalt pavement structure interior along with depth change rule and determining the position with the maximum shear. The paper analyzes the influence on shear stress by the factors of asphalt layer thickness, different loading and modulus, the change of shear stress peak of asphalt pavement structure interior and influencing factor is attained. On the other aspect, the main factors of influencing asphalt mixture shear strength are analyzed, evaluating the test methods of the ability to reduce deformation of the asphalt mixture. Using triaxial repeated load creep test, uniaxial penetration test and rutting test, the author analyzes the shearing properties between high viscosity base asphalt mixture,asphalt mixture for paving heavy traffic road and SBS modified asphalt mixture by general comparative study,for providing reference about application and research of high viscosity base asphalt in our road.Research found that using high modulus of asphalt concrete pavement structure, mechanical indicators has obvious advantages. It's an effective measure to improve the structure of the shear. For the adjustment to high pressure tires under high temperature and heavy loading, the high-intensity and high modulus of the material should be using on asphalt pavement ,especially surface layer and middle layer. Improve shear strength of asphalt mixture in the high shear stress region by high viscosity base asphalt or modified asphalt is very effective.