Research On Microcracking Technique Of Cement Treated Aggregate Base Material

Cement treated aggregate base material tend to produce shrinkage cracks during the early,and then lead to the occurrence of reflective cracks in pavement.Based on this,this paper proposed a new technique of relieving the reflective cracking of asphalt pavement at cement stabilized base---Microcracking technique.Microcracking technique referred to the vibratory roller was used to pass to the cement-treated base after a shoar stage of 1 to 3 days to create a fine network of cracks to avoid the severe wide or long cracks due to its contraction.After microcracking,the loss of mechanical strength at the base was temporary,the mechanical strength could gradually restore along with the age,and the main factors of affecting its restor ability including mixture structure type,cement dosage,curing time and microcracking-damaged degree etc.To better study the microcracking technique,needing researche on the mechanical strength,shrinkage characteristics of microcraked-base and mechanical behavior of asphalt pavement at microcraked-base.This paper mainly focuses on the following contents:(1)Based on the microcracking technology and its mechanism,Analying the main influence factors of microcracking technique,and the test scheme was proposed.At the same time through a lot of experiments,the corresponding relationship between the microcracking-damaged degree and the vibration time under the certain vibration parameters was found.(2)Making specimens of diffirent microcracking-damaged degree,then the mechanical performance tests,including compression strength,cleavage strength,modulus of compression strength resilience and shrinkage test of the specimens under different cement dosages,different curing time and different microcracking-damaged degree were researched.Througe analyzing development of mechanical strength and the change of the shrinkage performance,summing up the law of the mechanical changes of the cement treated aggregate base material of diffirent microcracking-damaged degree.(3)According to the law of the mechanical changes of the cement treated aggregate base material of diffirent microcracking-damaged degree,analyzing the mechanical behavior of the asphalt pavement structure under the standard axle load and the different overload levels by the KENPAVE pavement analysis software.These mechanical behavior mainly included the maximum shear stress,the maximum tensile stress and the pavement deflection of the asphalt pavement structure.(4)Combining the application of the microcracking technology in the Wu Qiao section pavement overhaul engineering of 104 national highway and the software analysis and laboratory test,the paper discussed the practical application of microcracking technology.The ideal comparing results between the experimental datas with software simulation datas providing reliable basis for the application and research of the microcracking technique in practical engineering.