Effect of aggregate contact characteristics on densification properties of asphalt mixture
Effect of aggregate contact characteristics on densification properties of asphalt mixture
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集料接触特性对沥青混合料致密化性能的影响
DOI：
10.1016/j.conbuildmat.2019.01.023
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发表时间：
2019-04-20
影响因子：
7.4
通讯作者：
Rao, Wenyu
中科院分区：
文献类型：
--
作者：
Li, Jiange;Li, Peilong;Rao, Wenyu
沥青混合料的密实性是集料接触作用的外在表现，包括压实过程中集料间的摩擦、互锁、错位以及沥青结合料的粘结等。沥青结合料对高温下的接触作用也有润滑作用。为了研究集料接触特性对沥青混合料密实性能的影响，研制了集料接触装置，进行了不同条件下的集料接触试验。根据接触试验曲线得到两个参数F和E，F是指由摩擦力和互锁力组成的最大接触力，E是指整个试验过程中所需的能量。考虑到沥青结合料在高温下的润滑，MF和ME指的是干混合料，而AMF和AME指的是沥青混合料。通过对致密化曲线的分析，得到了致密化工艺参数。探讨了集料接触参数与沥青混合料密实度参数之间的关系。结果表明：随着沥青混合料最大公称粒径的增大，集料间摩擦力和联锁力增大，MF和ME值也随之增大。沥青结合料在高温下对集料接触具有显著的润滑作用。级配密实的沥青混合料接触作用润滑充分，易发生压实。与试验温度和沥青用量相比，混合料的级配及其NMAS更容易影响接触作用，对沥青混合料的密实性能有显著影响。(C)2019爱思唯尔有限公司版权所有。
The densification properties of asphalt mixture are an external manifestation of aggregate contact action, including the friction, interlocking and dislocation of aggregates as well as the cohesion of asphalt binder during compaction. The asphalt binder also has a lubrication effect on the contact action at the high temperature. To investigate the effect of aggregate contact characteristics on the densification properties of asphalt mixture, an aggregate contact device was developed and aggregate contact tests were conducted on different conditions. Two parameters, F that refers to the maximum contact force composed of friction and interlocking force and E that refers to the required energy during the whole test, were gained according to the contact test curve. Considering the lubrication of asphalt binder at the high temperature, the MF and ME refer to the dry mixture, while the AMF and AME refer to the asphalt mixture. The densification parameters were obtained by means of analyzing the densification curves. Then the relationships between the parameters of aggregate contact and those of densification of asphalt mixture were discussed. The results indicate that the aggregate contact action composed of friction and interlocking force increases with the enlargement of nominal maximum aggregate size (NMAS) of the asphalt mixture, and the values of MF and ME increase with the increase of NMAS. The asphalt binder has a significant lubrication effect on the aggregate contact at the high temperature. The contact action of asphalt mixture with a dense gradation is lubricated enough is prone to be compacted. Comparing to test temperature and asphalt content, the gradation of mixture and its NMAS are more easily to affect the contact action, which has the significant effect on the densification properties of the asphalt mixture. (C) 2019 Elsevier Ltd. All rights reserved.