自反应型高模量沥青的技术性能评价

李炳南¹，耿立涛^2*，彭佳琳¹，王风姣¹，徐万雷¹

1.山东金曰交通发展集团有限公司，山东 济南  250101；2.山东建筑大学交通工程学院，山东 济南  250101

摘要：为解决直投高模量沥青混合料技术存在的添加剂利用率低、混合料低温性能和疲劳性能差等问题，采用低密度乙烯-苯乙烯共聚物类高模量剂制备自反应型高模量沥青及其沥青混合料并评价其技术性能，在纯搅拌工艺下制备3种自反应型高模量沥青HMB6、HMB7和HMB8，高模量剂在自反应型高模量沥青中的质量分数分别为6%、7%、8%，基于微观和理化特性分析高模量剂的分散状态及改性机理，结合宏观性能测试优选高模量剂的合理质量分数，以优选的自反应型高模量沥青HMB7制备并评价高模量沥青混合料的路用性能。结果表明：自反应型高模量沥青的改性过程为高模量剂的物理作用和其与沥青组分化学反应的综合结果；优选的高模量剂在沥青混合料中的质量分数为7%，为干法高模量剂用量的50%~80%，此时高模量剂的微观分散效果及低温性能较理想，且高温等级比采用传统高模量剂时提高1个等级；相应的高模量沥青混合料除高温性能优势外，其低温破坏应变比传统的干法高模量沥青混合料增大18%，疲劳寿命为后者的2~3倍。

关键词：低密度乙烯-苯乙烯；高模量剂；自反应型高模量沥青；微观性能；理化性能；路用性能

Performance evaluation of self-reactive high modulus asphalt

LI Bingnan¹, GENG Litao^2*, PENG Jialin¹, WANG Fengjiao¹, XU Wanlei¹

1. Shandong Kingyue Transportation Development Group Co., Ltd., Jinan 250101, China;

2. School of Transportation Engineering, Shandong Jianzhu University, Jinan 250101, China

Abstract: To address the issues of low additive utilization poor low temperature and fatigue performance in high modulus asphalt mixture, for direct application, a self-reactive high modulus asphalt and asphalt mixture are preparedusing low-density ethylene-styrene copolymer-based high-modulus agents,and their technical performance is evaluated. Three kinds of self-reactive high modulus asphalt are prepared with rather lower content (6%, 7% and 8%) of low-density ethylene-styrene copolymer as high modulus agent by pure mixing process, then the dispersion state and modification mechanism of high modulus agent are analyzed based on microscopic and physicochemical properties. The reasonable content of high modulus agent is selected based on the results of macroscopic performance test. Furthermore, the high modulus asphalt mixture with the preferred modifier content is prepared and its pavement performance is evaluated by laboratory tests. Results show that the modification process of self-reactive high modulus asphalt is a combination of the physical action of the high modulus agent and the chemical reaction between the asphalt binder and the modifier. The preferred high modulus agent content is 7% (by mass of the asphalt), which is 50%-80% of the modifier content in the dry-process. In this condition, the microscopic dispersion effect of the high modulus agent and the low-temperature performance of high modulus asphalt are desirable, and the PG high-temperature grade of high modulus asphalt is improved by one grade compared with that of the conventional high modulus asphalt. In addition to its superior high temperature performance, the high modulus asphalt mixture with optimum modifier content exhibited an 18% improvement in low-temperature destructive strain relative to conventional high modulus asphalt mixture with dry-process, while also achieving a 2 to 3 times extension in fatigue life.

Keywords: low-density ethylene-styrene copolymer; high modulus agent; self-reactive high modulus asphalt; microscopic property; rheological characteristics; pavement performance