内养护混凝土复合溶液下的耐酸腐蚀性能

发布时间：2018-03-04 08:01

本文选题：内养护混凝土　切入点：预湿轻细骨料　出处：《混凝土》2017年08期 　论文类型：期刊论文

【摘要】：采用预湿粉煤灰陶砂作为轻细骨料取代混凝土中的部分砂和石子,额外的引入水量可以完全消除混凝土自收缩以起到内养护的效果。通过室内加速腐蚀试验,研究了水灰比为0.36的内养护混凝土和普通混凝土在盐酸溶液(pH=2、4)、盐溶液(6%NaCl)、酸和盐的复合溶液(6%NaCl,pH=2、4)侵蚀后,抗压强度随时间的变化规律及原因。试验结果表明,在相同的腐蚀试验条件下,内养护混凝土的耐酸性腐蚀性能优于普通混凝土。同时发现,复合溶液对混凝土的劣化作用大于相同pH值的盐酸溶液,腐蚀过程中H~+和Cl~-的侵蚀是双重的,溶液的侵蚀速率不仅取决于H~+浓度,也与Cl~-浓度有关。微观结构观测表明,轻细骨料与浆体的界面过渡区致密均匀,因此其替代了大量薄弱的普通骨料界面过渡区有利于改善混凝土的抗渗透性。并且内养护技术在收缩调控、抗开裂性能上具有显著优势,对耐酸腐蚀性能有积极影响。
[Abstract]:Using prewet fly ash ceramic sand as light fine aggregate to replace part of sand and stone in concrete, the extra amount of water can completely eliminate the self-shrinkage of concrete so as to achieve the effect of internal curing. The variation of compressive strength with time after erosion of internally cured concrete and ordinary concrete with water-cement ratio of 0.36 in hydrochloric acid solution (pH = 2), salt solution (n = 6), sodium chloride solution (n = 6), and complex solution of acid and salt (NaClC + pH ~ (2 +) ~ (2 +)) has been studied, and the results show that the compressive strength of concrete and ordinary concrete with water cement ratio of 0.36 are changed with time. Under the same corrosion test conditions, the acid corrosion resistance of inner cured concrete is better than that of ordinary concrete. It is also found that the degradation of concrete by composite solution is greater than that of hydrochloric acid solution with the same pH value. The corrosion rate of solution is not only dependent on the concentration of H ~, but also depends on the concentration of Cln-. The observation of microstructure shows that the transition zone between light fine aggregate and slurry is dense and uniform. Therefore, it replaces a large number of weak transition areas of common aggregate interface to improve the penetrability of concrete, and the internal curing technology has significant advantages in shrinkage control and cracking resistance, and has a positive effect on acid corrosion resistance.
【作者单位】：清华大学土木工程系土木工程安全与耐久教育部重点实验室;山东高速云南发展有限公司;
【分类号】：TU528

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