盐湖卤水侵蚀喷射混凝土宏观性能及微观结构

发布时间：2018-05-28 08:41

本文选题：喷射混凝土 + 干湿循环　；参考：《西安建筑科技大学学报(自然科学版)》2017年05期

【摘要】：通过对普通混凝土、普通喷射混凝土和钢纤维喷射混凝土的质量损失率、相对抗压强度、相对动弹性模量、损伤层厚度、X射线衍射分析(XRD)和扫描电子显微镜(SEM)结果进行分析,研究了(干湿循环+盐湖卤水侵蚀)共同作用下喷射混凝土的宏观性能和微观结构.结果表明:宏观性能方面,质量损失率、相对抗压强度和相对动弹性模量均呈现出先增长后下降的趋势,损伤层厚度为普通混凝土普通喷射混凝土钢纤维喷射混凝土;微观结构方面,喷射混凝土中发现的侵蚀产物硅灰石膏,其CO_3~(2-)来源于混凝土内部分含碳酸盐骨料或干燥过程中发生的碳化,由于侵蚀前普通混凝土和普通喷射混凝土存在很多毛细孔,导致其比受钢纤维约束而较为致密的钢纤维喷射混凝土更易遭受盐湖卤水的侵蚀.
[Abstract]:The results of mass loss, relative compressive strength, relative dynamic elastic modulus, thickness of damage layer and X-ray diffraction (XRD) and scanning electron microscope (SEM) of ordinary concrete, ordinary shotcrete and steel fiber sprayed concrete were analyzed. The macroscopic properties and microstructure of shotcrete under the combined action of dry and wet circulation salt lake brine erosion were studied. The results show that the mass loss rate, relative compressive strength and relative dynamic elastic modulus all show a tendency of first increasing and then decreasing, and the thickness of the damage layer is ordinary concrete sprayed concrete steel fiber sprayed concrete. In terms of microstructure, wollastonite paste, the corrosion product found in shotcrete, is derived from carbonation of some carbonate aggregate in concrete or during drying. Due to the existence of many capillary holes in ordinary concrete and ordinary shotcrete before erosion, they are more vulnerable to salt lake brine than steel fiber confined steel fiber sprayed concrete.
【作者单位】：西安建筑科技大学土木工程学院;西部绿色建筑重点实验室协同创新中心;结构工程与抗震教育部重点实验室;
【基金】：国家自然科学基金(51278403) 教育部创新团队发展计划(IRT13089)
【分类号】：TU528.53

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