ABSTRACT

In this study, optimum bitumen content (OBC), an important parameter on Marshall Design is described with a mathematical model by using statistical design method. The effects of independent variables such as number of blows, temperature, additive rate and bitumen content are analysed. The simultaneous optimisation of the dependent variables such as practical specific gravity, voids, voids of filled with asphalt cement, Marshall stability, flow and Marshall coefficient is determined with the central composite design. The optimum conditions are detected with 70 blows, temperature of 160°C, additive amount of 10% and OBC of 4.484%. The desirability function is applied to determine local optimisation points. Following the model application, practical specific gravity is estimated to be 2.418 g/cm³ with voids of 4%, voids of filled asphalt of 71.74%, Marshall stability of 1138.4 kgf under optimum conditions. While it is necessary to pour 126 samples to achieve a result with these variables in Marshall Design under normal conditions, the results are achieved just by pouring 30 samples thanks to the models established.

摘要

在这项研究中，使用统计设计方法通过数学模型描述了最佳沥青含量（OBC），这是马歇尔设计中的一个重要参数。分析了独立变量的影响，例如吹塑次数，温度，添加速率和沥青含量。中心复合设计确定了相关变量的同时优化，例如实际比重，空隙，沥青水泥填充空隙，马歇尔稳定性，流量和马歇尔系数。通过70次吹塑，160°C的温度，10％的添加量和4.484％的OBC来确定最佳条件。期望函数用于确定局部优化点。根据模型应用，实际比重估计为2.418 g / cm ³在最佳条件下，空隙率为4％，填充沥青的空隙为71.74％，马歇尔稳定性为1138.4 kgf。在正常条件下，需要在Marshall Design中倒入126个样品才能获得这些变量的结果，但由于建立了模型，仅需倒入30个样品即可获得结果。