Study On The Test Of Vibratory Compaction For Cement Stabilized Gavel

vibratory roller had been in general used in congtrcuction of road,at peresent.Heavy Rammer method was used to determine the standard of compactness and molding specimen by still compressive force in laboratory testing of semi-rigid type base material,which leads to inadaptability.There were some defects in the design methodology of semi-rigid type base,at peresent.Such as the inconsistency of compaction mode between field compaction and laboratory conpaction,the standard of compactness was too low,the content of cement was too high,grading limit was too broad in norm.There were lots of cracks in semi-rigid type base before asphalt surface course was spreaded;the compressive strength of field specimen is more hinger than that of molding specimen by still compessive force in laboratory; the phenomenon of more than hundred compactness was universal,by using existing field compacting equipment.The parenchyma was the standard of compactness determined by Heavy Rammer method was too low.Adequate compaction of base was disregarded frequently,because compactness is easy to get. The laboratory test device for semi-rigid type base material was required to update,in order to simulate field construction machinery better. Compaction mechanics of vibrating compactor and the surface-vibrating instrument is the same.This paper analyzes the test results on the basis of the two mathematical models, which called spring model and vibration model of the surface-vibrating instrument, and then gets the influence relation between the compaction effect and the basic mechanical parameters of the surface-vibrating instrument, at the same time recommends a vibrating compaction standard about the laboratory test of the cement stabilized macadam material, and gives a comparative analysis on the decay situation of the gradation and the strength increase law of the specimen which molded by vibration method and static pressure method.comparing with conventional design method(Heavy Rammer+ still compessive compaction),the energy of virbrating compaction was greater,it result in larger dry density,lowwer optimum moisture content,fewwer content of cement,so virbrating compaction could resolve the problem of the standard of compactness was too low,the content of cement was too high by using onventional design method.When cement stabilized macadam material was designed by vibration method, basal compactness could get to 98% without extra requirement of rolling,the strength of specimens which come from field and vibratory compaction in laboratory were equivalence,and cracks in base were fewwer.It can get good economic performance,by using vibration methodology to design semi-rigid type material.