| Along with the constantly growing need of our country transportation,especially dramatically increased of the overloading vehicles,which will have a significant impact on the service life of the road,and it requires more in-depth research on the capacity of the load mixture resistance for the pavement structure designers,and the main part of the bear loads in the mixture is the coarse aggregate,its performance is closely related to quality of the road surface.In order to improve the efficiency of the use of aggregate,and ensure the engineering quality of asphalt roadbed,a related research on the coarse aggregate crushing value is particularly important.This paper mainly aims at the weakness of crushed value of coarse aggregate concerning the relevant specification,based on the overhaul project of the Lei-yi expressway,analyzing influencing factors of crushed value of the basalt coarse aggregate for asphalt pavement.Based on influencing factors and experiment of crushed value of single size aggregate,experimental procedure and analysis method concerning different size of coarse aggregate(4.75 mm to 9.5mm、9.5mm to 13.2mm and 13.2mm to 16mm)is determined under different working conditions.Influencing degree and changing law of the load size,needle flake particle,high temperature(paving temperature 160℃)and strength of parent rock on crushed value of coarse aggregate is analyzed;meanwhile,by analyzing influencing factors of mixture concerning multi-gradation aggregate on crushed value shows that crushed value of two gradation of coarse aggregate after mixing decreasing with the coarse aggregate content increasing,while the crushed value is always between that of different degree of coarse aggregate,particle size was verified through experiment(2.36 mm to 4.75mm)aggregate division belongs to the fine aggregate is reasonable.Fifteen test programs were proceeded to investigate crushed value with multi-degree admixture,nevertheless,by introducing uniformity coefficient CU,the crushed value and CU presents liner relation,and then verifying the feasibility of the crushed value and excellent gradation via gray theory.Meanwhile,by simulating the process of mixture mixing,paving and rolling,comparative test of crushed value with target proportioning and production proportioning was proceeding under normal temperature and high temperature,and the crushed value under high temperature is put forward.On the basis of the research on the engineering problems of the asphalt pavement under the hot rolling of crushed aggregate,choose the the test section for test,and according to the results of the tests,puts forward quality control suggestions,to ensure the construction quality of pavement. |
