低温地区橡胶热再生沥青混合料的参数优化及其工作性

Parameter Optimization of Rubber Hot Recycled Asphalt Mixture and the Workability Study in Low Temperature Regions

为了优化低温地区橡胶热再生沥青混合料的制备参数,以河北张承高速某试验段为依托工程,以抗弯拉强度为评价指标,通过室内小梁弯曲试验,结合数理统计方法分析不同胶粉掺量、胶粉细度以及RAP料掺量对橡胶热再生沥青混合料弯拉强度的影响权重及影响规律,并探讨混合料在研究区域的工作性能。研究结果表明,相同条件下AC13级配橡胶热再生沥青混合料的弯拉强度要优于AC16级配的混合料;对于AC13级配,当胶粉掺量为5%,胶粉细度为20目,RAP料掺量为35%时,相应的混合料弯拉强度相对最好。对于AC16级配,当胶粉掺量为5%,胶粉细度为40目,RAP料掺量为35%时,相应的混合料抗弯拉性能相对最好;随着胶粉掺量的增加,两种级配(AC13和AC16)所制备的橡胶热再生沥青混合料的抗弯拉强度均呈减小趋势,胶粉掺量对橡胶热再生沥青混合料弯拉强度的影响最大,RAP掺量次之,胶粉细度量的影响最小。胶粉掺量对AC13级配的橡胶热再生沥青混合料弯拉强度的影响效应要高于对AC16级配混合料的影响效应;当橡胶热再生沥青混合料的拌和温度在150~190℃之间变化时,其和易性随着拌和温度的增大而不断改善,当拌和温度相同时,AC13级配混合料的施工和易性要优于AC16级配的混合料;橡胶热再生沥青混合料在研究区域具有较好的适用性。

In order to optimize the preparation parameters of rubber hot-mix recycled asphalt mixture in low temperature regions,this paper took one test section of Zhang-Cheng highway in Hebei province as a project case.Through the beam bending test,this paper took the flexural-tensile strength as evaluation index,combined the mathematical statistics method to analyze the influence rule of different rubber crumb content,rubber crumb fineness and recycle asphalt pavement content on the flexural-tensile strength of rubber hot-mix recycled asphalt mixture,and discussed the workability in research area.The results showed that the flexural-tensile strength of rubber hot-mix recycled mixture with AC13 grade is better than that of AC16 grade in the same conditions;For AC13 grade,when the rubber crumb content was 5%,the rubber crumb fineness was 20 meshes,and the recycle asphalt pavement content was 35%,the low-temperature performance of the corresponding asphalt mixture was the best.For AC16 grade,with 5%rubber crumb content,40 mesh rubber crumb fineness,and 35%recycle asphalt pavement content,the low-temperature performance of the corresponding asphalt mixture was the best;With the increase of rubber crumb content,the flexural-tensile strength of the rubber hot-mix recycled mixture with two grade(AC13 and AC16)both showed a decreasing tendency;The decreasing rank of the influential effect of each influence factor on the low temperature crack resistance of rubber hot recycled mixture was rubber crumb content,recycle asphalt pavement content and rubber crumb fineness.The influential effect of rubber crumb content on the low temperature crack resistance rubber hot recycled mixture with AC13 grade was bigger than that of AC16 grade;When the mixing temperature of rubber hot-mix recycled mixture was range from 150℃~190℃,the workability was continuous improvement with the increasing of mixing temperature;When they were conducted at the same mixing temperature,the workability of rubber hot recycled mixture with AC13 grade was better than that of AC16 grade;The rubber hot-mix recycled mixture had good applicability in research region.