超细废旧沥青颗粒直投式再生研究

Study on Direct Injection Regeneration of Superfine Waste Asphalt Particles

为实现废旧沥青混合料多元精细化再生利用,通过水洗法筛选出超细废旧沥青颗粒。将筛选出的超细废旧沥青颗粒分别以0%、0.2%、0.4%、0.6%、0.8%、1.0%的掺量直投式加至AC-20沥青混合料,通过残留稳定度试验、冻融劈裂强度比试验、车辙试验和低温弯曲试验研究了超细废旧沥青颗粒掺量对沥青混合料路用性能的影响,并基于沥青混合料空隙率及超细废旧沥青颗粒改性沥青蠕变性能等微细观角度对其影响机理进行了分析。结果表明:超细废旧沥青颗粒可同时提高沥青混合料的高、低温性能;掺加超细废旧沥青颗粒的沥青混合料空隙率与其低温性能呈良好的负相关性,空隙率减小是其低温性能提高的主要原因;掺入超细废旧沥青颗粒,其中存在的老化沥青与新沥青融合导致沥青不可恢复蠕变柔量下降,高温性能提高。该研究成果为废旧沥青路面材料精细化再生利用提供了思路。

In order to realize the multi-refinement recycling of waste asphalt mixture,the superfine waste asphalt particles are screened out by the water washing method.The selected particles were added to AC-20 asphalt mixture by direct injection with dosage of 0%,0.2%,0.4%,0.6%,0.8%and 1.0%respectively.Tests of residual stability,melt splitting strength ratio,rutting and low temperature bending were used to study effect of the particle content on the road performance of asphalt mixture.Based on the micro perspective of asphalt mixture porosity and creep property of superfine waste asphalt particle modified asphalt,the influence mechanism was analyzed.The results show that the particles can improve the high and low temperature performance of asphalt mixture at the same time;The asphalt mixture porosity mixed with superfine waste asphalt particles has a good negative correlation with its low temperature performance,which is that the porosity reduction is the main cause of low temperature performance improvement;The fusion of aged asphalt in the mixed superfine waste asphalt particles and the new asphalt leads to the asphalt irrecoverable creep compliance decrease and the high temperature performance improvement.The research results provide ideas for the refined recycling of waste asphalt pavement materials.