沥青再生剂扩散程度评价与影响因素研究

Study on the Evaluation of Regenerant Diffusion in Aged Bitumen and Its Influencing Factors

关键词:  道路工程  再生沥青混合料  老化沥青  再生剂  软化点试验  扩散系数

Key words:  road engineering  regenerating bituminous mixture  aged bitumen  regenerant  softening point test  diffusion coefficient

摘要:

设计了模拟再生剂在老化沥青中扩散过程的试验方案，并基于软化点试验结果进行回归分析，得到了反映再生剂在老化沥青中扩散程度的相对指标——扩散系数p；分析了再生剂品种、沥青老化程度和环境温度对扩散系数p的影响；基于劈裂强度试验，分析了再生剂扩散程度对再生沥青混合料性能的影响.结果表明:再生剂黏度越大或沥青老化程度越深，再生剂在老化沥青中的扩散程度越低；环境温度和扩散时间的增加能显著提高再生剂的扩散程度；再生剂在老化沥青中的充分扩散有利于再生沥青混合料强度的提高.

Abstract:

Experiment was designed to simulate diffusion of regenerant in aged bitumen. Based on the results of softening point test and through regressive analysis, the diffusion coefficient p was used to show the characteristics of diffusion of the regenerant in aged bitumen. The influences of regenerant types, aged degree and environment temperature on the diffusion coefficient p were analyzed. Based on the splitting strength test, the influence of regenerant diffusion on the performance of regenerating bituminous mixture was analyzed. According to the results, the greater the viscosity of regenerant is, the higher the aged degree of bitumen will be, and the lower the regenerant diffusion degree in aged bitumen will be. Meanwhile, increase of environment temperature and diffusion time will enhance the diffusion of regenerant remarkably, and the complete diffusion of regenerant in aged bitumen will be favorable for the improvement of regenerating bituminous mixture strength.