焚烧飞灰颗粒对沥青混合料水稳定性的影响

Influence of Incineration Fly Ash Granulated Particles on Water Stability of Asphalt Mixture

关键词:  道路工程  焚烧飞灰  沥青混合料  造粒预处理  水稳定性  影响机制

Key words:  road engineering  incineration fly ash  asphalt mixture  granulation pretreatment  water stability  influence mechanism

摘要:

为了实现焚烧飞灰（IFA）在沥青路面中的资源转化，将焚烧飞灰与水泥造粒以及与水泥、硅灰、粉煤灰造粒，研究掺有造粒颗粒沥青混合料的水稳定性以及冻融劈裂试验条件对其水稳定性的影响机制.结果表明：焚烧飞灰造粒后，氯离子浸出率分别降低了56.76%、59.12%；冻融劈裂试验条件对焚烧飞灰/水泥颗粒沥青混合料水稳定性影响顺序为抽真空过程＞冷冻过程＞击实次数，抽真空过程破坏造粒颗粒表面沥青膜，导致可溶氯盐溶出，氯盐溶液在冻融过程中产生的冻胀、盐胀与腐蚀综合作用是导致沥青混合料内部结构受损关键因素；焚烧飞灰与水泥、硅灰、粉煤灰造粒的方法能有效改善沥青混合料的水稳定性.

Abstract:

In order to realize the utilization of incineration fly ash （IFA） in asphalt pavement， the IFA was granulated with cement， and silica fume， coal ash. The water stability of asphalt mixture with granulated particles and the influence mechanism of freeze thaw splitting test conditions on its water stability were studied. The results show that after IFA is granulated， the chloride ion leaching rate decrease by about 56.76% and 59.12% respectively. The order of the influence of freeze thaw splitting test conditions on the water stability is vacuum extraction process>freezing process>compaction times. During the process of vacuum extraction， the asphalt film on the surface of IFA/cement granulated particles is destroyed， thus the soluble chloride is dissolved out， the combined action of frost heaving， salt heaving and corrosion of chloride solution in the course of freeze thaw cycle is the key cause of damage to the internal structure of asphalt mixture. The method of co-granulation of cement， silica fume， coal ash and IFA can effectively improve the water stability of asphalt mixture.