Study On Compaction Quality Of Soil-aggregate Mixture By Tests

With the rapid development of our contry's highways of high class, it has entered hilly lands and mountain areas, so we might face the situation many times that using the soil-aggregate mixture to fill embankment. As the grade composition and water content of soil-aggregate mixture are quite uneven, and so different with the common fine earth, the problem about the defination of the standard dry density, the suitability of test method and the rationality of evaluation index would definitely exist if still using the compaction standard and test methods of fine earth. Based on indoor and outdoor tests, this paper has been conducting studies on the compaction quality of soil-aggregate mixture when used as fill material in highway embankment and puts forward the compaction quality control methods of soil-aggregate mixture embankment.First, the author analyses the basic characteristic, structure type and strength compositon of soil-aggregate mixture theoretically.Second, we obtain the influencing pattern on the maximum dry density of soil-aggregate mixture caused by the factors of coarse aggregate content, maximum particle size,water content, graduation, based on the compaction tests on soil-aggregate mixture of different maximum particle size and coarse aggregate content, employing the heaw-duty compaction instruments. In addition, the influence of coarse aggregate content on the CBR, the unconfined compressive strength and the modulus of resilience of soil-aggregate mixture is studied by test.Third, with the comparision of the maximum dry densities obtained from the similar graduation method and the structure analysis method, the method of using pugging test to determine the the maximum dry densities is put forware.At last, the thesis evaluates the current compaction quality control index and test method of earth-aggregate composite embankment; it establishes the relationship between the amout of settlement, rate of settlement and dry density through indoor and outdoor tests; and it verifies the reliability of surface sedimentation method as the quality control test method of soil-aggregate mixture.