The Fatigue Life Research On The Asphalt Pavement With Cement Stabilized Recycled Base

Rely on the projiect The Research of the Fatigued Performance of the Cold-recycled Base Material with Asphalt Pavement in Liaoning Provincce of Liaoning province highway administration bureau, the paper conducts the experimental research on the fatigued performance of the cold-recycled base material based on the Shenying xian test road as object of study, studies and forecasts the fatigued of pavement structural material through combinative the test and simulation. Concrete research content as follows:(1) Conducting pavement performance test of two kinds of RAP materials, the one contains only surface material (RAP-S for short), the other contains surface and base material (RAP-P for short). The paper summarizes the variation laws between strenght and stiffness performance and stabilization and curing period by the tests included unconfined compressive strength test, splitting strength test and compressive resilience modulus test of the two kinds RAP materials, and also analyses the difference of strenght and stiffness between cold-recycled material and semi-rigid base material.(2)Based on the same graduation and cement dosage, fatigue tests of RAP-P materials are conducted on MTS810 fatigue testing machine.All of them, cement dosage is 5%,the ratio of degree of finish (clastic rock) among the cold-recycled material are 0%,20% and 40%., the fatigue life equation is Established by fatigue test, fatigue performance is conducted.The paper obtains the fatigue performance of the testing material are:the cold-recycled base material which includs 40% gravel,the cold-recycled base material which includs 20% gravel,the unalloyed cold-recycled base material; however , the fatigue performance of the cold-recycled base material reduce by the stress level lower obviously.(3)Based on the same asphalt pavement structure, the paper conducts structural analysis for the cold-recycled base and semi-rigid base by ABAQUS finite element software, the analysis shows that the tensile stress of the cold-recycled base bottom is lower than that of the semi-rigid base.(4)Leading the results of fatigue test and asphalt pavement analysis to nsoft fatigue analysis softwares, we can obtain the conclusion, the fatigue life of the pure cold-recycled material is lower than the cold-recycled material which includes gravel.(5)By fatigue test results,calculating the linear equation between allowable tensile stress and the logarithm of loading number,the equation shows that with the increase of loading number,the reduce of allowable tensile stress of the pure cold-recycled material is faster than that of the cold-recycled material which includes gravel.(6) Based on the fatigue test, the paper analyzes the fatigue life of the same asphalt pavement structure, in which the base is the pure cold-recycled material or semi-rigid base material, the results show that the fatigue life of the asphalt pavement structure with pure cold-recycled base is lower than that of the semi-rigid base.(7)The fatigue life of Shenying test road is analyzed, contrast with practical fatigue life, find out that the practical fatigue life is lower than that of theoretical analysis,the phenomenon is caused by unreasonable of job practice and construction quality. The paper shows that the cement stabilized recycled material belongs to semi-rigid base material. But the fatigue life of the asphalt pavement structure with pure cold-recycled base is lower than that of the semi-rigid base.