对沥青混合料的抗车辙性能进行优化设计,设定骨架密实和设计8%空隙率2个优化条件,据此提出新型矿料级配设计方法——分级掺配法。矿料成型采用改进的干捣实方法,根据集料分界点分2步逐级掺配集料,粗集料部分每级集料掺配比例依据骨架判断公式和高斯拟合结果得出,细集料部分每级掺配比例依据高斯拟合结果得出,进而确定粗细集料各自总的质量百分率,由此得到一条骨架密实型级配曲线,并进一步按照优化条件确定油石比。用成型试件对混合料沥青膜厚度、矿料间隙率、空隙率、动稳定度等各项性能指标进行验证,结果表明沥青混合料抗车辙性能较好,功能化设计方法能有效地改善沥青混合料的性能。
The optimal design method of rut resistance property of asphalt mixture was introduced. Taken the 8 % air voids and skeleton dense structure of asphalt mixtures as the restrict parameters, a new aggregate gradation design method (multilevel mixing method) was put forward, and the aggregates were formed by using the dry-rodding method. The coarse and fine aggregates were mixed respectively according to the critical grain size. The mixture ratios of coarse aggregates were obtained and validated according to the skeleton judgement formula and Gauss fitting result.The mixture ratios of fine aggregates were obtained according the Gauss fitting result. Then, the quality percentages of coarse and fine aggregates were determined and the skeleton dense gradation curve was obtained accordingly, and the asphalt-aggregate ratio of asphalt mixture was calculated according to the optimization condition. The performance indexes of asphalt mixture, such as asphalt film thickness, VMA, air voids and dynamic stability were verified by testing the specimen. The result shows that the functional design method of asphalt mixture is useful and effective.