开级配沥青混合料损伤-自愈合行为影响因素研究

Research on Factors Affecting the Damage-healing Behavior of Open-graded Asphalt Mixtures

开级配沥青混合料因具有较大的结合料黏度及孔隙率,其损伤-自愈合特性具有特殊性。基于4点弯曲疲劳试验,研究了影响大孔隙开级配排水式沥青磨耗层(OGFC)自愈合性能的因素,并通过在愈合温度、愈合湿度以及损伤程度等多种因素条件下研究了OGFC自愈合特性的影响规律。结果表明:愈合温度对OGFC的自愈合性能具有积极影响;高温愈合条件下,OGFC的自愈合效率随公称最大粒径的增大而减小;低温条件下,不同公称最大粒径的OGFC自愈合效率差异较小,自愈合速率较为缓慢;愈合湿度和损伤程度对OGFC的自愈合性能具有消极影响,当OGFC的愈合湿度超过50%,其自愈合效率显著下降,当损伤程度为75%时,OGFC-16混合料的愈合效率骤降至5%左右,表明损伤程度越大,OGFC自愈合越困难。

The damage-self-healing property of open-graded asphalt mixture is special for its large binding material viscosity and void ratio In this study,four-point bending fatigue test was conducted to analyze the factors that affect the self-healing performance of the open-graded friction courses(OGFC)with large void ratio.The influence rule of healing temperature,healing humidity,and damage degree on the self-healing efficiency of OGFC were studied.The results showed that the temperature had a positive effect on the self-healing performance of OGFC.It should be noted that the self-healing efficiency of OGFC decreases with the increase of the nominal maximum size of aggregate(NMSA)at high temperatures.Whereas the self-healing efficiency of OGFC with different NMSA shows slight differences,and the self-healing rate is slow at low temperatures.In addition,the healing humidity and damage degree exhibited a negative impact on the self-healing efficiency of OGFC.Specifically.The self-healing efficiency of OGFC decreases sharply when the healing humidity exceeds 50%.When the damage degree exceeds 75%,the healing efficiency of the OGFC-16 reduced to about 5%.It indicated that the more severe the damage,the more difficult the self-healing of OGFC.