混合料生产过程中骨料破碎对HMA体积特性的影响

The Effect of Aggregate Degradation on the Volumetric Properties of Hot-Mixed Asphalt

对沥青混合料生产和铺筑过程中集料破碎降解现象与生产摊铺不同阶段的混合料的体积特性进行了研究,结果发现:①在矿料的转运、提升与拌合过程中会产生显著破碎降解;②集料的最大公称粒径(NMAS)与混合料厂拌生产过程中的集料的破碎降解率无关;③虽然集料破碎降解是集料类型的函数,但粗集料洛杉矶磨耗损失与细集料磨耗试验均不能用来预测所研究类型集料的降解情况;④实验室取样与运料车取样成型试件的空隙率与矿料间隙率存在显著差异,研究没有找到通过采用混合料体积参数来预测厂拌过程中集料破碎降解情况的方式。

mixture＇s volumetric properties at different stages of the process of asphalt production and construction, obtained are several conclusions, which are as follows： （1）Various degrees of degradation of aggregate particles may occur in hot-mixed asphalt （HMA） production in the mixing and compacting processes, especially in the process of aggregate being lifted, hauled, mixed and rolled. （2）The NMAS （nominal maximum aggregate size） of the aggregate does not significantly contribute to the observable aggregate degradation. （3）Aggregate degradation is determined to be a function of aggregate sources; however, it appears that neither L.A. Abrasion nor the Micro-Deval tests can be used to predict aggregate degradation of the sources in-vestigated. （4）The laboratory prepared and truck sampled VV and VMA results differ significantly, however a means of predicting changes in the mixture volumetric properties as a result of aggregate degradation in the plant is not found yet.