The Study On Composition Of Grading Crushed Rock With Low Cement Dosage And The Construction Technique

Since the reform and opening up, in the construction of highway asphalt pavement get unprecedented high speed development, the overall level of road infrastructure realized the historical spanning. Semi-rigid base is widely used in the road structure in our country, this is mainly due to the semi-rigid base pavement have stronger bearing capacity, good stability and durability advantages.Semi-rigid base have more outstanding advantages, but its also has certain defects, mainly displays in:semi-rigid base itself is easy to produce dry shrinkage cracks, temperature, and then under the action of vehicle load, the reflection to the surface, form the reflection crack; Semi-rigid base at the same time also not easy to repair, and thus affect the service life of the asphalt road surface, and water damage and other problems. In addition, the damage of semi-rigid base after repairing difficulty.In recent years, people found between asphalt layer and semi-rigid base set up graded gravel flexible primary can effectively reduce the reflection crack. But its shortcomings are mainly as follows:small modulus of resilience, stress diffusion capacity and plastic deformation. So for the application of graded crushed stone, have some limitations.Comprehensive and grading macadam semi-rigid base and the basic characteristics, this paper puts forward the concept of a flexible base, the so-called half flexible base, is between semi-rigid material and flexible material of a kind of structure form. Low dose cement stability grading macadam by reduce the dosage of cement in the mixture, diffusion semi-rigid base, so as to achieve the purpose of preventing reflection cracks. In this paper low cement dosage stable grading macadam base materials for the indoor mixture ratio design, and 7 d unconfined compressive strength test,At the same time this paper relying on fushun shen loop line overhaul project, road paving a 2.5 km experiment, this paper Shen Huan northern on-site detection and long-term observation test section, the content mainly includes:low cement dosage stable grading macadam base compaction degree detection, modulus of resilience; Long-term observation test road flatness detection and crack. And draw lessons from the current specification and the maturity of the existing research results, with low cement dosage stable grading macadam base construction technology is studied, mainly include:the mixture mixing, mixture of loading and transport, the mixture paving and rolling, and curing four aspects. At the same time to control the construction quality control index and standard study, comprehensive research of micro bonding of graded crushed stone base construction technology and control targets, to ensure low cement dosage stable grading macadam base construction quality and application is of great significance.Finally, the test lulu long-term observations were made with performance, and verify the low cement dosage stable grading macadam base inhibitory reflex the effect of the crack.