再生矿质混合料拌和过程热-机械力效应及对沥青混合料性能的影响

Thermal-mechanical Effect on Properties of Asphalt Mixture of Recycled Aggregate during Heating & Mixing Process

研究了再生矿质混合料在预热拌和过程中的热-机械力效应对其级配和沥青混合料性能的影响,结果表明:在边加热边搅拌过程中,由于热-机械力效应,再生矿质混合料中细颗粒和矿粉明显增多,按级配中值设计得到的矿质混合料中矿粉含量甚至超出其级配上限要求,在进行再生矿质混合料配比设计时,应考虑热-机械力效应的影响,适当减少矿粉用量。与采用天然骨料相比,采用再生骨料作为矿质混合料,按级配中值设计时,其最佳沥青用量明显增大,而马歇尔稳定度明显减小,考虑热-机械力效应进行配比设计后,可有效减小其最佳沥青用量,提高马歇尔稳定度,且可大幅度提高沥青混合料动稳定度。

Thermal-mechanical effect during heating properties of the RA and the hot-mixed asphalt admixture the passing percent in each sieve rises obviously, and the mixing process of recycled aggregate on are studied in this paper. The results show that smaller the sieve size is, the higher the passing percent due to the thermal-mechanical effect. The passing percent in 0. 075ram sieve may even surpass the upper limit while designing based on the median value of the gradation requirement of AC-16I. It is suggested that the initial designed passing percent at each sieve size should be a little lower than the expected, which can assure that the the heating ＆ mixing process, thus final actual passing percent can the optimum asphalt content of nearly reach the expected value after the HMA can be lowered.