厂拌热再生过程中旧矿料颗粒的迁移行为

为提高热再生混合料的均匀性与生产质量,设计一种以回收沥青路面材料(reclaimded asphalt pavement, RAP)模拟制备、利用磁铁分离新旧矿料及迁移程度测试为关键步骤的室内试验,并通过该试验分析了RAP掺量、拌和时间及沥青用量对不同规格旧矿料颗粒迁移程度的影响。试验结果表明:热再生沥青混合料中旧矿料颗粒不能全部脱离原矿料,其迁移程度约为55%~75%;RAP掺量对迁移程度影响不大,随着拌和时间和沥青用量的增加,迁移程度不断增大;适当延长拌和时间,掺加新沥青或再生剂以及增加沥青用量可以促进旧矿料有效迁移,提高热再生沥青混合料的均匀性。

Migration behavior of reclaimed mineral aggregate in process of central plant hot recycling

To improve the qulity of central plant hot recycling asphalt mixture, a test was designed, including key procedures such as fabricating reclaimded asphalt pavement(RAP), separating new aggregate from mixture and testing migration quantity. By in-laboratory tests, the influences of mixing amount of RAP, mixing time and asphalt content on migration quantity of reclaimed aggregates were evaluated. The results indicated that the reclaimed fine particle mineral aggregates could not disengage from the coarse ones totally during the mixing process of hot recycling asphalt mixture, and the migration quantity of that was about 55% to 75%; the mixing amount of RAP would not change the migration quantity, but longer mixing time and more asphalt content could improve the migration quantity. Migration of reclaimed mineral aggregates would be accelerated by lengthening mixing time properly, adding new asphalt or recycling agent and increasing asphalt content, resulting uniformity of central plant hot asphalt pavement.