沥青混合料目标配合比设计的最佳沥青含量范围估算

针对沥青混合料目标配合比设计阶段马歇尔方法确定最佳沥青含量时因拟定的沥青含量范围宽而导致试验工作量大的情况,提出了估算最佳沥青含量范围的问题.即以空隙率和矿料间隙率计算公式联合解得沥青含量表达式,再依据体积指标的标准要求估算出最佳沥青含量范围.理论分析和工程实例表明,估算法必然能找到最佳沥青含量所在的局部小范围;然后在此小范围内进行马歇尔试验确定最佳沥青含量,可大大减少试验工作量,缩短试验时间.

Estimation of Optimum Asphalt Content Range of Hot Mix Asphalt in Objective Mix Design

In objective mix design period by use of Marshall Method for hot mix asphalt,the range of initial asphalt content for determining optimum asphalt is relatively large and results in a great deal of tests,so a new method which can find a narrow range of optimum asphalt content is established in this paper.An expression of asphalt content can be obtained from the computational formula of the Air voids(AV) and the voids in the mineral aggregate(VMA).Using the expression and the standard of this volumetric index the method can find a range of optimum asphalt content.The theoretical analysis and engineering examples(including examples of Marshall Method and Superpave system) indicate that the range is narrow,which can consequentially include the optimum asphalt content.Then using Marshall Method to search the optimum asphalt content based on this small range,the workload and time of the tests are reduced significantly.