Research of low-temperature fracture performance of reclaimed asphalt mixture based on cohesive zone modeling
Cohesive zone model(CZM)has been widely adopted in the cracking studies of hot mix asphalt,but there are few studies focused on the cracking of reclaimed asphalt mixture based on CZM.In this paper,the stochastic algorithm and the coordinate control method were used to establish the semicircular bending model of the reclaimed asphalt mixture including the RAP aggregate and the virgin aggregate,and the model was divided into two types,i.e.,the identical distribution of aggregates and the random distribution of aggregates.The effect of RAP(0,25% ,50% ,75% ,100% ,mass fraction)was investigated on the fracture parameters at-10℃,including stress intensity factor(KIC),fracture energy(GF)and cracking resistance index(ICR).The results show that specimens without the incorporation of RAP exhibit the superior fracture resistance in terms of KIC,GF and ICR.With the increase of RAP mass fraction,KIC,GF and ICR all decrease remarkably,indicating the low-temperature fracture resistance is degraded.The fracture parameters obtained by using the finite element model are consistent with those of the laboratory tests.Compared with the identical distribution model of aggregates,the variability coefficient of each evaluation index of the random distribution model of aggregates is larger,indicating that the distribution state of aggregates shows a certain influence on the cracking results,and sufficient calculation time is the key to accurate calculation.When there are enough calculation samples,the changes of the fracture parameters of the two types of models are consistent,which can effectively evaluate the fracture performance of recycled asphalt mixture.
reclaimed asphalt mixturestress intensity factorfracture energycracking resistance indexcohesive zone model
万方数据
维普
