Effects of Long-term Hot Water Immersion on Fatigue Performance of Hot Recycled Asphalt Mixtures
The hot-recycling of RAP(reclaimed asphalt pavement)can realize the resource utilization of road solid waste,and meet the requirements of green and sustainable development.However,the durability of hot recycled asphalt mixture with high content RAP is an urgent problem to be solved.According to the megathermal and humid climate characteristic,the strength reduction,fatigue characteristic and self-healing performance after long-term water immersion were investigated for hot recycled asphalt mixture contained 30％RAP as well as for conventional asphalt mixture without RAP.Test results indicate that hot recycled asphalt mixture contained 30％RAP has higher indirect tensile strength and fatigue life compared with conventional asphalt mixture.After 60℃water immersion,the strength and fatigue life is obviously declined.The residual percentage of strength and fatigue life shows a linear relation,which allows for the strength to fatigue life prediction.The conventional asphalt mixture has a higher healing level compared with hot recycled asphalt mixture contained 30％RAP.However,this difference of self-healing capacity is found to be limited after water immersion.On the contrary,during four-point bending fatigue test,hot recycled asphalt mixture contained 30％RAP only has about half of the bending fatigue life of conventional asphalt mixture.After 14 days of 60℃water immersion,the bending fatigue life of the former is further reduced to one third of fatigue life of the latter.Both types of mixture have a considerable healing performance,while the fatigue damage is difficult to heal when the specimens were kept in water.The prediction model of modulus reduction over water immersion time is developed to quantitatively evaluate on the effect of megathermal and humid climate on the modulus reduction.Furthermore,this model could also be used to predict the residual fatigue life of hot recycled asphalt mixture.
hot recycled asphalt mixturehigh-temperature water immersionstrength reductionfatigue performance
万方数据
维普
