Influence Of Cement-fly Ash Stablized Crushed Stone Base For Asphalt Pavement Structure

Cement Stabilized Graded crushed stone Base is an important form of semi-rigid base, as having a nice overall mechanical performances and stability to be asphalt pavement structure widely used in China. In recent years, semi-rigid asphalt road surface crack has become such a major defect of pavement structure, causing pavement damage.Using fly ash to improve the performance of Cement Stabilized Graded crushed stone Base. finished the laboratory experiments about materials of cement-fly ash stabilized gravel base; and also carry out the calculation of semi-rigid base pavement structure by computer simulation using FEM. Comparing the results of vehicle stress and temperature stress in different combinations of pavement structure layers, moreover, finished the test road construction of cement-fly ash treated base as having mechanical characteristics and experimental data to be analyzed. The research concluding as followings:(1) It reduced the early performance of the cement stabilized crushed stone roadbase by using fly-ash. But because of synthetic effect of the following two aspects---fly ash activity effect and filling effect. Cement-flyash treated roadbase has higher strength, compactness, lower modulus, swell-shrink characteristic and better pavement performances.(2) It was indicated by mechanical analysis that: cement-fly ash stabilized crushed stone base can significantly reduce critical stress of asphalt surface crack and the crack tip of the stress intensity factor, reduce and delay the reflection crack of asphalt pavement, improving the long-term performance.(3) The construction of cement-flyash graded broken stone roadbase did not increase the difficulty in construction, It`s easy to control the construction quality, and has obvious social and economic benefits.