Shrinkage Performance Research On Low Cement Dosage Graded Crushed Rock Base Material

With the leapfrog development of highway in our country, semi-rigid base asphalt pavement with its advantages of high bearing capacity, low cost, has become the mainstream asphalt roadbed of highway structure in our country. Semi-rigid base is easy to appear, however, dry shrinkage and temperature shrinkage cracks, and the reflection to the surface to form cracks.Pavement cracks will not only reduce the overall flatness of the surface but also cause water to enter the pavement structure and lack of timely discharge, which would further reduce the strength of the grassroots. But so far, still have not found semi-rigid base asphalt pavement to prevent cracks in an effective manner. In recent years, many scholars in our country is put forward by using graded crushed stone base instead of semi-rigid base, thereby reducing the cracks of reflection, but the grading macadam roadbase though can effectively reduce the reflection crack. But the shortage of its own strength, stiffness characteristics, its can only be used in the lower level or the path of light traffic, not widely used.Low cement dosage graded crushed rock base is between semi-rigid base and flexible base of a structure form, by reducing the dosage of cement in the mixture, thus reducing the shrinkage coefficient and enhance the anti-cracking performance of mixture. The mixture under the premise of meeting the strength requirement, strengthen its ability to resist contraction, thus reduce crack generation and transmission. Low cement dosage stable (?)ding macadam base not only can effectively reduce the reflection crack, at the same time due to the mixed with a small amount of cement, the strength is better than that of graded crushed stone base, solve the low stiffness of asphalt pavement on the base of the grading macadam, adapt to the traffic problem of poor ability of overload.The first chapter is the introduction, this paper illustrates the research significance, research status at home and abroad and the research content. The second chapter, three, four, five, respectively for Low cement dosage graded crushed rock material strength and mixture ratio test, the shrinkage mechanism of mixture, shrinkage and shrinkage performance are analyzed. The sixth chapter of low cement dosage graded crushed rock crack resistance comprehensive evaluation. The seventh chapter through the finite element software ABAQUS, analysis of low cement dosage graded crushed rock inhibitory reflex crack effect. Chapter 8 provides entity engineering test road construction and site test. The ninth chapter summarizes the thesis research the main conclusion, and put forward some Suggestions for further study.