温拌沥青混合料的压实特性与难易系数

为了研究温拌沥青混合料的压实性能及其可压实的难易程度, 选用3种同品牌温拌沥青(ACMP1、ACMP2与ACMP3) 和2种热拌沥青(70^#基质沥青与SBS改性沥青), 制备了AC-13C型沥青混合料, 采用马歇尔击实试验, 变化不同的击实次数和击实温度, 测试了马歇尔试件的压实度和稳定度, 分析了其变化规律, 建立了压实度与击实次数的指数回归关系, 引入了压实成长曲率因子, 定义了压实难易系数。试验结果表明: 沥青混合料的压实度随着击实次数的增加而呈指数增长, 初期增长较快, 后期较慢, 且最终趋于稳定; 在击实温度为90℃¹50℃的范围内, 压实度随着击实温度的升高呈线性增长; 马歇尔稳定度随压实度增大呈线性增长变化, 符合传统研究结果; 温拌沥青混合料的压实难易系数比热拌沥青混合料降低了13.5%~18.5%, 具有较小的压实难易系数, 更容易压实。

Compaction characteristic and operability factor of warm bituminous mixture

To study the compaction characteristics and compaction operability of warm bituminous mixture, AC-13 C mixtures were made based on 3types of warm mix bitumens with the same brand (ACMP1, ACMP2 and ACMP3) and 2kinds of hot mix bitumens (70 # base bitumen and SBS modified bitumen).The compactness and stability of each Marshall specimen were measured by Marshall compaction test, their change rules were analyzed in different initial compaction temperatures and times, and the exponential regression relationship between compactness and compaction times was proposed.The curvature factor on compaction growing was applied and the operability factor was defined to evaluate the compaction workability.Test result shows that the compactness of bituminous mixture increases exponentially with the increase of compaction times, increases faster in the early stage, slows in the late stage, and stabilizes finally.The compactness increases linearly with the increase of initial compaction temperature within 90 ℃-150 ℃.Marshall stability increases linearly with the increase of compactness in accordance with traditional research results.The operability factor of warm bituminous mixture decreases by13.5%-18.5% compared with hot bituminous mixture, so it is easier to be compacted.