带初始损伤混凝土受硫酸盐侵蚀劣化的机理分析

发布时间：2018-03-18 02:17

本文选题：初始损伤　切入点：干湿循环　出处：《建筑材料学报》2017年05期 　论文类型：期刊论文

【摘要】：通过测量混凝土的质量变化量和相对动弹性模量,研究了带初始损伤混凝土在干湿循环作用下受硫酸盐侵蚀的劣化规律,同时利用压汞法(MIP)、扫描电镜(SEM)和电子能谱技术(EDS),探究分析了含初始损伤混凝土在硫酸盐侵蚀作用下的孔结构和腐蚀产物组分的变化.结果表明:随着初始损伤度的增加和水灰比的增大,混凝土受硫酸盐腐蚀劣化加剧;损伤度为20%的混凝土受硫酸盐侵蚀150d后的相对动弹性模量降低至12.3%,试件部分表面剥落;大掺量矿渣混凝土抗硫酸盐侵蚀能力提高;随着腐蚀时间的增加,混凝土孔隙率增大,大孔数量增多;高水灰比混凝土内部腐蚀产物主要是石膏,低水灰比混凝土内部腐蚀产物主要是钙矾石.
[Abstract]:By measuring the mass variation and the relative dynamic elastic modulus of concrete, the degradation law of concrete with initial damage caused by sulfate erosion under the action of dry and wet cycles is studied. At the same time, the changes of pore structure and corrosion product components of concrete with initial damage under sulfate erosion were investigated and analyzed by means of mercury injection method, scanning electron microscopy (SEM) and electron spectroscopy (EDS) technique. The results show that with the initial damage degree, the change of pore structure and corrosion product composition of concrete with initial damage is investigated. And the increase in the water-cement ratio, The relative dynamic elastic modulus of the concrete with damage degree of 20% was decreased to 12.3d, and the surface of the specimen was flaked off, and the resistance to sulfate corrosion of the concrete with large amount of slag was improved, and the corrosion resistance of the concrete with 20% damage degree decreased to 12.3d after the sulphate corrosion of the concrete was aggravated by sulphate corrosion. With the increase of corrosion time, the porosity of concrete increases and the number of large pores increases, and the internal corrosion product of high water-cement ratio concrete is gypsum, and the internal corrosion product of low water-cement ratio concrete is ettringite.
【作者单位】：东南大学材料科学与工程学院;
【基金】：国家重点基础研究发展计划(973计划)项目(2015CB655102) 国家自然科学基金资助项目(51378116)
【分类号】：TU528

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