不同外掺剂改善再生沥青混合料路用性能研究

Study on Road Performance of Recycled Asphalt Mixture by Different Additives

对分别添加玄武岩纤维和高模量剂的再生沥青混合料进行路用性能试验,并与同时添加2种外掺剂的再生沥青混合料进行对比,采用高温车辙、低温弯曲、浸水马歇尔、冻融劈裂以及四点弯曲疲劳等一系列室内试验,分析了其高温稳定性、低温抗裂性、水稳定性和抗疲劳性能。试验数据表明,玄武岩纤维和高模量剂能有效增强再生沥青混合料的高温稳定性和抗疲劳性,但低温抗裂性能提升效果不明显。而将2种外掺剂复掺运用到再生沥青混合料中,其各项性能特别是抗疲劳性和低温抗裂性得到明显提升。2种外掺剂复掺不仅能有效改善再生沥青混合料的路面性能,还能最大限度提升旧沥青混合料的使用数量,在保障工程质量的前提下,旧料掺量最大可达到50%。

Road performance tests were carried out on the recycled asphalt mixture with basalt fiber and high modulus agent respectively. The results were compared with the recycled asphalt mixture with two additives added at the same time. High temperature rutting,low temperature bending,flooding Marshall,freeze-thawing splitting and four-point bending fatigue and a series of laboratory tests were adopted,which analyzed its high temperature stability,low temperature crack resistance,water stability and fatigue resistance. Experimental data shows that basalt fiber and high modulus agent can effectively enhance the high temperature stability and fatigue resistance of recycled asphalt mixture,but the effect of low temperature cracking resistance is not obvious enough. However,when the two kinds of admixture are added into the recycled asphalt mixture,their performances,especially the fatigue resistance and the lowtemperature crack resistance are obviously improved. The two kinds of admixture complex doping not only can effectively improve the performance of recycled asphalt pavement,but also maximize the use of old asphalt mixture. Under the premise of ensuring the project quality,the aggregate content can reach up to50%.