| The base,which is the main bearing layer of the pavement structure is very important to the life of the pavement.In China,the semi-rigid base is most widely used,but the problems such as cracks have been the barrier to its development.After recent years of experiment and engineering application,the cement-fly ash stabilized aggregate has been found excellent in stabilizing macadam base.It has obvious advantages in anti-cracking and resistance to erosion.Meanwhile,it is low costing.This paper is based on the Reconstruction and Extension Project of Shi-An Freeway,referring to construction technology of other kinds of bases and the successful experience of cement-fly ash stabilized aggregate base.Performance of raw materials should be qualified.Under this precondition,and by analyzing the gel materials’ function in mixture,the quality of mixture structure,the ratio of concrete,the proportion of the cement-fly ash and concrete,aggregate scope of gradation are finally determined.Then come up with the appropriate mix proportion.The test results and problems in test section help to determine the equipment setting as well as work division.They also help to make sure the parameters of equipment mixers,pavers and rollers.The compaction technology on tire roller and single vibratory road rollers is proposed.Meanwhile,the construction technology of cement-fly ash stabilized base is also summarized.Double laying is used and factors to which must pay attention are pointed out.Comparing with traditional technology,it has various advantages,such as better contact condition on interface,less man power and human resources,shorter construction time.As for the mixture segregation and out of flatness,many factors,from scope of gradation,equipment mixer,mixture transformation to its paving and compaction are all considered to found out the solution.At last,combining design and criterion request,keypoints about construction quality control and inspection criterion of engineering entity are put forward. |
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