水泥乳化沥青混凝土细观损伤及微观性能

Meso-damage and Micro-properties of Cement Emulsified Asphalt Concrete

为了给水泥乳化沥青混凝土研究及应用提供技术支持,基于计算机断层成像(CT)技术及扫描电镜(SEM)、X射线衍射(XRD)及热重(TG)等测试手段,对水泥乳化沥青混凝土的细观损伤规律及微观性能进行了试验研究.结果表明:连续加载过程中,水泥乳化沥青混凝土试件上部分断面的CT平均数变化较小,下部分变化较大、损伤严重.试件的破坏过程分为压密、扩容、裂纹扩展及破坏4个阶段,损伤过程表现出塑性特征,这源于水泥乳化沥青混凝土低强度、低弹模的力学性能.乳化沥青与黏土不参与水泥水化,破乳后的沥青包裹水泥颗粒,减缓了水泥早期水化速度;后期水化迅速,结构逐渐致密,部分沥青与Ca(OH)_2,C_3S,C_2S及钙矾石等水化产物相互镶嵌.

Based on CT, SEM, XRD and TG, the meso-damage and micro-properties of cement emulsi- fied asphalt concrete were studied, offering the technique support for the related researches. The result shows that compared to the higher part of the cross-sections of specimens, the lower parts have a larger change in terms of CT average number and have a more serious damage in the process of continuous load- ing. Concrete specimen has experienced four stages of condense, expansion of volume, crack rapid prop- agation and failure. The plastic characteristics are showed during the meso-damage process, which is owing to the low strength and modulus of this concrete. Emulsified asphalt and clay aren＇t involved in hydration of the concrete. The asphalt encapsulates cement particles after demulsification, so that the early hydration rate of cement is decreased. The late hydration is quick, and concrete structure becomes compact, asphalt and main hydration products, such as Ca（OH）2, C3S, C2S and calcium ettringite products are mutually inlaid.