关键词: 水泥稳定碎石;微裂技术;干缩特性;干缩试验;数值模拟

Abstract: In order to reduce the early dry-shrinkage stress of cement stabilized macadam,the effect of micro-cracking to cement stabilized macadam dry-shrinkage properties was studied.Firstly,through the indoor dry-shrinkage test based on the method of static resistance,the dry-shrinkage strain curve of cement stabilized macadam beam specimens under different levels of micro-cracking was established,which provided a reference basis to test and verify the reliability of the numerical simulation results;Secondly,by using the finite element software ABAQUS,the three-dimensional mode of cement stabilized macadam beam under different levels of micro-cracking was set up to simulate the dry-shrinkage test in the indoor environment and make the statistical analysis of the numerical simulation results.It concluded the early dry-shrinkage properties of the cement-stabilized macadam after micro-cracking and the rules of dry-shrinkage strain with the changing of micro-cracking degree.The results show that the micro cracks can effectively reduce dry-shrinkage strain of the materials,and the shrinkage strain of cement stabilized macadam decreases with the increase of micro-cracking degree.Meanwhile,the values of dry-shrinkage strain show an increasing trend of the quadratic function with the increase of the crack spacing.It is validated respectively from the perspectives of the indoor test and numerical simulation that the micro-cracking technology could effectively reduce the early dry-shrinkage strain of the cement stabilized macadam and then make the phenomenon of stress concentration reduce or even disappear.It also proves that the micro-cracking technology could effectively prevent the formation and expansion of the shrinkage cracks in the practical engineering.

Key words: cement stabilized macadam;micro-cracking;dry-shrinkage performance;dry-shrinkage test;numerical simulation