大掺量RAP温再生沥青混合料设计及路用性能研究

Road Performance Evaluation of High RAP Content Asphalt Mixture

为提高沥青路面回收材料(RAP)的利用效率和应用水平,利用实验室自主合成的温再生剂与新沥青混合制备温再生沥青,并设计拌制温再生沥青混合料;采用黏温曲线法预估拌和、体积参数法验证拌和及成型温度;马歇尔设计法确定RAP掺量为50%、60%和70%的最佳沥青用量;分别采用车辙试验、低温小梁弯曲试验和冻融劈裂试验对温再生沥青混合料的高温性能、低温性能和水稳定性能进行评价,并与相同配合比条件下热再生沥青混合料的路用性能进行对比。研究结果表明:黏温曲线法可适用于温再生沥青混合料的温度控制;随着RAP掺量的增加,温再生沥青混合料的高温性能逐渐提高,低温性能和水稳定性能逐渐降低;与热再生沥青混合料相比,温再生沥青混合料的高温性能略差,低温性能和水稳定性能表现良好;当RAP掺量为70%时再生沥青混合料的各项路用性能均能够满足规范要求,可为工程生产和质量控制提供参考。

Aiming to enhance the utilization efficiency and application level of asphalt pavement materi-al,warm recycled asphalt is prepared by laboratory synthetic warm recycled agent and new asphalt,and warm regeneration asphalt mixture is designed.V iscosity-temperature curve method is used to predict,volume pa-rameter method is used to verify the mixing temperature and compaction temperature,the Marshall Design method is selected to measure the optimum asphalt content of warm recycled asphalt mixtures with RAP content of 50%,60%and 70%.Rutting test,low temperature beam bending test and freeze-thaw spliting test are used to evaluate the high temperature performance,low temperature performance and water stability perform-ance of warm regeneration asphalt mixture,which are compared with hot regeneration asphalt mixture under the same mix proportion.The results show that the viscosity temperature curve method is suitable for tempera-ture control of warm regeneration asphalt mixture.With the increasing of RAP content,the high temperature performance of warm regeneration asphalt mixture gradually improving,and the low temperature performance and water stability performance gradually are decreasing.Compared with hot regeneration asphalt mixture,the high temperature performance of warm regeneration asphalt mixture is slightly worse,low temperature perform-ance and water stability are better.Considering the road performance of warm regeneration asphalt mixture comprehensively,when the RAP content is 70%,the road performance of asphalt mixtures meet the specifica-tion requirements,which provides a reference for construction and quality control in actual projects.