石墨烯复合改性橡胶沥青热老化及紫外老化性能研究

Study on the Thermal Aging and Ultraviolet Aging Performances of Graphene Modified Rubber Asphalt

为研究石墨烯对橡胶沥青的复合改性在抵抗热老化与紫外老化性能方面的影响效果,制备了不同掺量石墨烯的复合改性橡胶沥青,通过对复合改性橡胶沥青进行TFOT老化试验与紫外光辐射老化试验,采用热老化与紫外老化后残留物的针入度比、软化点增量、质量损失比以及紫外老化后残留物黏度增长率、车辙因子老化指数RAI,不可恢复柔量几和变形回复率R为指标,对其抗热老化与抗紫外老化性能进行比对分析研究,结果表明,掺加石墨烯进行复合改性可有效改善橡胶沥青抵抗热老化与紫外老化的能力。其中热老化与紫外老化后残留物的针入度比均有增大,紫外老化后的残留物涨幅达15%,软化点增量与质量损失比也持续降低,紫外老化后质量损失比可达75%;其黏度增长率随着石墨烯掺加持续降低,降幅可达70%;基于紫外老化前后的复合改性沥青流变试验,车辙因子老化指数RAI与不可恢复柔量几随石墨烯掺量提高连续降低、其变形回复率R值均逐渐增长,表明掺加石墨烯能有效提高橡胶沥青抵抗热氧老化与紫外老化的能力,延缓老化进程,延长路面使用寿命。

In order to study the effect of graphene on rubber asphalt composite modifceation in terms of resistance to thermal aging and ultraviolet aging,based on the preparation of composite modified rubber asphalt with different contents of graphene,the TFOT aging test and ultraviolet radiation aging test are carried out.The penetration ratio,softening point increment and mass loss ratio of the residual after thermal aging and ul-traviolet aging,the viscosity growth rate,the rutting factor aging index RAI,the unrecoverable flexibility J and the deformation recovery rate R of residual after ulraviolet aging are used as indexes for the multi-level and multi-faceted comparative comparison analysis study of thermal aging resistance performance and ultravi-olet aging resistance performance.The results show that the composite modification with graphene can effec-tively improve the resistance of rubber asphalt to thermal aging and ultraviolet aging.The penetration ratio of residual after thermal aging and ultraviolet aging increases,and the increase of residual mass after ultraviolet aging reach 15%.The softening point increment and mass loss ratio also continue to decrease,and the mass loss ratio after ultraviolet aging reaches 75%.Its viscosity growth rate continued to decrease with the addition of graphene,with a decrease of 70%.Based on the rheological test of composite modified asphalt before and after ultraviolet aging,the rutting factor aging index(RAI)and unrecoverable flexibility(Jnr)of composite modified asphalt decrease continuously with the increase of graphene,and the deformation recovery rate(R)increases gradually.It shows that the addition of graphene can effectively improve rubber asphalt thermal oxy-gen aging resistance performance and ultraviolet aging resistance performance,delay the aging process and prolong the service life of pavement.