改性磷尾矿微粉沥青混凝土抗水损害性能研究

为能够对磷尾矿资源进行安全、有效的利用,该研究针对磷尾矿微粉在道路沥青中再利用时易团聚难分散的问题,对磷尾矿微粉进行改性处置后,以不同掺量加入沥青中制备磷尾矿微粉-沥青胶浆样品,采用动态剪切试验研究磷尾矿微粉对沥青高温流变性能的影响,综合基础物理性能和剪切流变性能分析其对沥青材料服役行为的影响机制。同时,基于开级配OGFC-16多孔沥青混合料的马歇尔稳定度试验和冻融循环劈裂试验,探究磷尾矿微粉对沥青混合料抗水损害性能的影响规律。研究结果表明,磷尾矿微粉具有比普通矿粉更大的比表面积,能够实现沥青的有效吸附并形成结构沥青,从而支撑磷尾矿微粉对沥青混合料抗水损害性能的改善作用。研究成果有望支撑磷尾矿微粉在道路工程中的规模化再利用。

In order to make safe and effective use of phosphate tailings resources,in this study,in order to solve the problem that phosphate tailings powder is easy to agglomerate and difficult to disperse when reused in road asphalt,phosphate tailings powder is modified and disposed.Phosphate tailings micro-powder-asphalt mortar samples were prepared by adding different amounts of phosphate tailings into asphalt,and the effect of phosphate tailings fine powder on the rheological properties of asphalt at high temperature was studied by dynamic shear test.The mechanism of its influence on the service behavior of asphalt materials was analyzed based on the basic physical properties and shear rheological properties.At the same time,based on the Marshall stability test and freeze-thaw cycle splitting test of open-graded OGFC-16 porous asphalt mixture,the effect of phosphate tailings on water damage resistance of asphalt mixture was explored.The results show that the phosphate tailings powder has a larger specific surface area than the ordinary mineral powder,which can effectively adsorb asphalt and form structural asphalt,thus supporting the improvement of phosphate tailings powder on the water damage resistance of asphalt mixture.The research results are expected to support the large-scale reuse of phosphate tailings in road engineering.