回收沥青材料性能及再生新沥青掺量试验研究

Study on the Performance of Recycled Asphalt Material and the Fresh Asphalt Content of Regeneration Asphalt Mixture

回收的废旧沥青混合料性能对再生混合料的设计与路用性能有重要影响。针对回收AC-16SBS沥青上面层混合料的沥青胶结料与集料的基本性能进行了分析,并研究了新沥青的掺量。结果显示:(1)回收沥青的25℃针入度、10℃延度、软化点以及沥青含量有不同程度的衰减,但基本均可再生;(2)回收粗集料的吸水率和黏附性指标变化不大,但针片状含量、压碎值以及洛杉矾磨耗值指标性能均有所降低,加入新集料后,可用在中下面层再生;(3)回收沥青混合料中大粒径集料较易细化成中等粒径的集料,中等粒径与小粒径集料变化不大;(4)混合沥青胶结料25℃针入度与10℃延度随着新沥青掺量的增大而增大,软化点随着新沥青掺量的增大而减小,并且具有良好的线性关系;仅从沥青常规指标恢复使用要求考虑,新沥青的掺量不宜低于50%。

The performance of recycled asphalt mixture is important to the performance of regeneration asphalt mixture in designing and using. This paper analyzed the binder an the aggregate performance of recy- cled AC - 16 SBS asphalt mixture above layer, and study the added volume of fresh asphalt. The results showed ： （ 1 ） The 25℃ penetration, 10 ~C ductility, softening point and asphalt content of recycled asphalt decreased in varying degrees, but it could be regenerated; （2） The water absorption and adhesion indicators of recycled coarse aggregate changed a little. But the needle sheetgaugetester content, crushing value and Los Angeles abrasion performance indicators decreased. It could be regenerated in the middle and bottom layer af- ter mixing new aggregate; （3） The large size particles of aggregate were prone to cracked into medium size particles, but the medium size and small size particles changed little; （4） The 25 ℃ penetration and 10℃ ductility increased as content of fresh asphalt mixture, while the softening point decreasing, and they have high linear relation. The fresh asphalt added volume should be no less than 50% to satisfied the conventional index requirements of asphalt using.