WTR/EVA复合改性沥青及沥青混合料性能研究

Study on Performance of WTR / EVA Composite Modified Asphalt and Asphalt Mixture

利用废旧材料对沥青进行改性,既符合绿色发展的新理念,还有利于沥青及沥青混合料性能的提升。探究WTR和EVA两种改性剂对沥青及沥青混合料性能的影响,应用DSR试验、BBR试验以及黏度试验评价改性沥青的高低温流变性能。此外,对沥青混合料的高低温性能、水稳性能以及抗老化性能进行了综合评价。试验结果显示:DSR试验和黏度试验结果表明,WTR和EVA均可有效提升沥青的高温性能;BBR结果显示EVA可有效提升沥青在低温下的应力消散能力。另外,15%WTR+4%EVA沥青混合料的动稳定度较基质沥青提高了225.4%,改性后沥青混合料的水稳定性以及抗老化性能均有一定程度的提升,经过15%WTR+6%EVA改性后沥青混合料的抗老化性能提升了39.5%。综上,WTR在提升高温性能方面起主导作用,而EVA在提升低温性能方面表现更优越。推荐WTR/EVA复合改性沥青的最佳掺量为15%WTR+4%EVA。

Utilized waste materials to modify asphalt not only conforms to the new concept of green development,but also improves the road performance of asphalt and asphalt mixtures.The purpose is investigation the influence of WTR and EVA on asphalt and asphalt mixture performance.Dynamic shear rheological test,Bending beam rheometer test and viscosity test are used to evaluate the high and low-temperature rheological properties of modified asphalt.In addition,a comprehensive evaluation of the high and low temperature performance,moisture susceptibility and aging resistance of the composite modified asphalt mixture was carried out.The test results suggested that both WTR and EVA could improve the properties at high temperature;EVA can improve the stress dissipation ability of asphalt effectively at low temperatures according to the BBR tests.In addition,the dynamic stability of 15%WTR+4%EVA asphalt mixture has increased by 225.4%compared with base asphalt mixture.Furthermore,the moisture susceptibility and aging resistance of the modified asphalt mixture have been improved to a certain extent,the aging resistance of asphalt mixture after modification by 15%WTR+6%EVA is 39.5%higher than that of base asphalt mixture.In summary,WTR plays a leading role in improving high temperature performance,while EVA performs better in improving low temperature performance.It is recommended that the optimal content of WTR/EVA composite modified asphalt is 15%WTR+4%EVA.