考虑胶浆黏附性的泡沫沥青冷再生混合料性能

The influence of filler-asphalt ratio, aging degree and temperature of aged asphalt on the bonding strength between the foamed asphalt mastics and aged asphalts was investigated based on orthogonal design method. The bonding strengths between the mastics and aged asphalts were obtained using a self-developed testing equipment. The impact of the three factors and the optimal level of each factor were determined using methods of range analysis and variance analysis. The optimal filler-asphalt ratio was obtained with a combination of the dry/wet indirect tensile strength(ITS) test of cold recycled mixture with foamed asphalt(CRMFA). Then, three kinds of mixing processes of CRMFA were proposed, and the performances of the samples produced by different mixing processes were investigated based on freeze-thaw tensile strength, wheel tracking and unconfined compressive strength tests. The results show that the adhesion of foamed asphalt mastics is most affected by filler-asphalt ratio, followed by temperature of aged asphalt, while the aging degree exhibits the minimal effect. The optimal levels of the three factors affecting the bond strength between the mastics and aging asphalts are 2:1 of filler-asphalt ratio+(85min RTFOT+10h PAV )aging degree of asphalt+50℃ of aged asphalt temperature, respectively. The optimal filler-asphalt ratio 2:1 is determined based on the dry/wet ITS test. Comparing with the performances of samples produced by the three different mixing processes, it is found that the mixing process displays a significant influence on the performances of mixtures. The mixing process that blending coarse aggregates together with RAP firstly, then adding fine aggregate, mineral powder and cement in turn, at last adding remaining asphalt for last mixing is the best process.