干燥环境下内养护混凝土收缩、强度及开裂性能

发布时间：2018-05-19 05:12

本文选题：内养护混凝土 + 预湿轻细骨料　；参考：《建筑材料学报》2016年05期

【摘要】：研究了掺入预湿轻细骨料(粉煤灰陶砂)的内养护混凝土与普通混凝土在不同干燥环境下的收缩和相对湿度发展、质量损失、强度发展及开裂风险.结果表明:当暴露在干燥环境时,内养护混凝土的相对湿度下降速率和总体收缩速率均大于普通混凝土,延长密闭养生时间至28d不能显著降低内养护混凝土的总体收缩;干燥环境下内养护混凝土更易失水,从而降低内养护效率;早龄期暴露于干燥环境下的普通混凝土和内养护混凝土的抗压强度和弯拉强度均显著降低;干燥环境下,内养护技术不能显著提高混凝土的抗开裂性能,但在不与外界发生水分交换的条件下,内养护混凝土未出现开裂.因此,内养护混凝土宜用于大体积混凝土或非表层的结构物混凝土中.
[Abstract]:The shrinkage and relative humidity development, mass loss, strength development and cracking risk of inner curing concrete and ordinary concrete mixed with pre-wet light fine aggregate (fly ash ceramic sand) under different dry conditions were studied. The results show that the decrease rate of relative humidity and the total shrinkage rate of internal curing concrete are higher than that of ordinary concrete when exposed to dry environment, and the total shrinkage of inner cured concrete can not be significantly reduced by prolonging the closed health time to 28 days. Curing concrete in dry environment is more likely to lose water, thus reducing internal curing efficiency; compressive strength and flexural strength of common concrete and internal cured concrete exposed to dry environment at early age are significantly reduced; under dry environment, Internal curing technology can not significantly improve the cracking resistance of concrete, but without water exchange with the outside world, there is no cracking in the internal curing concrete. Therefore, internal curing concrete should be used in mass concrete or non-surface structure concrete.
【作者单位】：清华大学土木工程系;
【基金】：国家自然科学基金资助项目(51578316)
【分类号】：TU755.7

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