辉绿岩集料和石灰岩集料混用路用性能研究

Road Performance of Mixed Diabase Aggregate and Limestone Aggregate

为解决部分地区辉绿岩集料在配合比设计过程中四档料均用辉绿岩集料易出现空隙率Va、矿料间隙率VMA和流值FL偏大的问题,结合工程实例,首先通过室内试验从辉绿岩的集料品质、粗集料压碎值、细集料棱角性、细集料粉尘含量和粉胶比、集料与沥青的粘附性及矿料级配等多方面论述了辉绿岩的集料特性对沥青混合料配合比设计的影响;其次,提出了采用石灰岩集料和辉绿岩集料混用的方法来提高混合料的和易性,降低矿料间隙率VMA和流值FL;再次,通过浸水马歇尔试验、劈裂试验和车辙试验验证了石灰岩和辉绿岩混用后,其沥青混合料的高温性能和水稳定性能均有不同程度的提高;最后,结合试验路铺筑和相关检测,总结说明了石灰岩集料和辉绿岩集料混用具有良好的路用性能,路面压实度、渗水系数、构造深度及抗滑系数等技术指标均良好,适用于高速公路上面层。

In the process of mix proportion design, using diabase in four aggregate grades may bringsome problems, such as the increasing of void fraction（Va）, voids in mineral aggregate （VMA） andflow value（FL）. To solve these problems, a study was conducted combining with an engineering example.Firstly, the influence of the diabase aggregate quality, crushing value of coarse aggregate, angularity offine aggregate, dust content and filler-bitumen of fine aggregate, adhesion of aggregates and asphalt, ag-gregate gradation, etc. on the design of mix proportion of asphalt mixture were expatiated on. Secondly,the method that mixing limestone aggregate and diabase aggregate was put forward for improving theworkability of mixture and reducing its VMA and FL. Thirdly, through Marshall immersion test, splittingtest and rutting test, it was verified that the high temperature performance and water stability of asphaltmixture were improved when the limestone and diabase were mixed together. Finally, combining with thepaving of test road and related testing, it was illustrated that mixing with limestone aggregate and dia-base aggregate could get good road performance, meanwhile such technical indicators as pavement com-paction, water penetration coefficient, depth and anti-sliding coefficient were all fine, which indicatedthat the mixing of limestone aggregate and diabase aggregate could be applied to top surface of express.way.