新型混凝土表面防护材料的研究

发布时间：2018-03-18 09:07

本文选题：氯离子侵蚀　切入点：砂浆保护层　出处：《硅酸盐通报》2017年07期 　论文类型：期刊论文

【摘要】：以纳米SiO_2、硅灰、粉煤灰作为矿物掺和料对水泥基材料进行改性,形成混凝土表面防护层。利用RCM法测定氯离子扩散系数,并通过SEM、XRD、DSC等手段研究改性水泥基材料的水化产物组成及微观结构,分析改善机理。结果表明:混凝土表面砂浆防护层能将混凝土抗氯离子侵蚀能力提升56.75%,并且这种提升效果随着粉煤灰、硅灰、纳米SiO_2的掺入更加明显,且其提升能力依次增加;粉煤灰依靠其微集料效应及填充效应,增强了水泥石的密实程度;纳米SiO_2、硅灰依靠其火山灰活性促进水泥的水化并产生二次水化,进而提升抗氯离子侵蚀能力。研究结果说明了利用无机矿物掺合料对水泥基材料进行改性形成防护层可明显提升混凝土的抗氯离子侵蚀能力,为进一步研究无机混凝土表面防护体系提供了研究基础。
[Abstract]:Cement based material was modified with nano-SiO2, silica fume and fly ash as mineral admixture to form concrete surface protective layer. Chloride diffusion coefficient was measured by RCM method. The composition and microstructure of hydration products of modified cement-based materials were studied by means of SEM XRDX DSC and so on. The improvement mechanism is analyzed. The results show that the concrete surface mortar protective layer can increase the resistance of concrete to chloride ion erosion by 56.75, and this lifting effect is more obvious with the addition of fly ash, silica fume and nanometer SiO_2, and its lifting ability increases in turn. Fly ash depends on its micro-aggregate effect and filling effect to enhance the compactness of cement stone, and nano-SiO-2, silica fume depends on its pozzolanic activity to promote cement hydration and produce secondary hydration. The results show that using inorganic mineral admixtures to modify cement based materials to form protective layer can obviously improve the resistance of concrete to chloride ion erosion. It provides a basis for further study of inorganic concrete surface protection system.
【作者单位】：武汉理工大学硅酸盐建筑材料国家重点实验室;武汉纺织大学;
【基金】：“十三五”国家重点研发计划(2016YFC0701003-05)
【分类号】：TU528

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