沥青发泡性能评价指标及优化设计研究

采用3种不同品种和标号的沥青进行发泡试验,分析了采用膨胀率、半衰期评价沥青发泡性能存在的问题,探讨了发泡指数的计算方法及其作为沥青发泡性能评价指标的适用性.结果表明:并非沥青温度越高其发泡性能越好;以膨胀率、半衰期指标设计最佳发泡用水量缺乏理论依据;采用不同回归方程对沥青泡沫衰变过程进行两阶段拟合,可获得较为准确的发泡指数,但并非发泡指数越大,沥青发泡性能越好,发泡指数应与膨胀率、半衰期结合用于沥青发泡性能的评价与优化设计.基于研究成果,提出了沥青发泡性能的优化设计方法.

Research on the Evaluation Index and Optimization Design of Asphalt Foaming Characteristics

Three types of asphalt were chosen to carry out foaming experiments. Problem of evaluation of asphalt foamability with expansion ratio and half life was analysed. The calculating method of foamed index and its applicability as evaluating index for asphalt foaming characteristics were also investigated. The results indicate that better foamability was not necessarily the direct result of higher asphalt temperature. It lacked theoretical basis to use expansion ratio and half life to determine the optimal water content. Two phase fitting with different curves to the decay process of foamed asphalt could achieve more accurate foamed index. However, higher foamed index did not necessarily mean better foamability. It is suggested that foamed index be combined with expansion ratio and half life to evaluate and design foamed asphalt. On the basis of the study in this paper, an optimal design for asphalt foamability was put forward.