Understanding the effect of curing age on the chloride resistance of fly ash blended concrete by rapid chloride migration test
Understanding the effect of curing age on the chloride resistance of fly ash blended concrete by rapid chloride migration test
复制标题
通过氯离子快速迁移试验了解养护龄期对粉煤灰掺合混凝土抗氯性能的影响
DOI：
10.1016/j.matchemphys.2017.05.011
复制
发表时间：
2017-08-01
影响因子：
4.6
通讯作者：
Xing, Feng
中科院分区：
文献类型：
--
作者：
Liu, Jun;Wang, Xiaodong;Xing, Feng
海洋混凝土结构在使用过程中，氯化物的侵入被认为是造成钢腐蚀的主要原因。粉煤灰可有效提高混凝土抗氯离子渗透性能。尽管利用快速氯离子迁移（RCM）试验对粉煤灰掺合混凝土复合材料的氯离子迁移行为进行了大量的研究，但在RCM试验系统下，养护龄期对粉煤灰混凝土中氯离子迁移的影响仍缺乏批判性的认识。本研究旨在通过RCM试验研究养护龄期对粉煤灰掺合混凝土抗氯离子性能的影响，同时考虑水胶比和粉煤灰掺量的影响。根据RCM试验结果，发现养护龄期条件对混凝土抗氯离子迁移性能的影响取决于粉煤灰掺入量。短养护龄期会导致低粉煤灰掺量混凝土氯离子迁移系数增大。但在高掺量粉煤灰的养护阶段，抗氯离子迁移能力仍可得到提高。无论混凝土中掺加多少粉煤灰，长期养护均有利于混凝土抗氯离子迁移。然而，在固化后期，随着固化时间的增加，这种积极作用变得不那么显著。并对混凝土微观结构进行了探讨，以阐明氯离子迁移的宏观行为。(C) 2017 Elsevier B.V.版权所有
Chloride ingress is considered as the most responsibility to steel corrosion for offshore concrete structure during service. Fly ash has been shown to effectively enhance the resistance of concrete to chloride penetration. Despite the numerous contributions of investigation regarding the chloride migration behavior of fly ash blended concrete composites by using rapid chloride migration (RCM) test, there is still a lack of critical understanding of curing age effect on the chloride migration in fly ash concrete under RCM testing system. The present study aims to investigate the effect of curing age on the resistance of fly ash blended concrete to chloride ion under RCM test, also considering the factors of water-to-binder ratio and fly ash content at the same time.Based on the RCM tested results, it is found that the effect of curing age condition on the chloride migration resistance is depended on the amount of fly ash incorporated in concrete. Short term curing age can lead to increase the chloride migration coefficient of concrete with low fly ash content. But resistance to the chloride migration can still be enhanced at this curing stage when high percentage of fly ash is supplied. Long term curing age can benefit the chloride migration resistance, regardless of how much fly ash is used in concrete. However, this positive effect becomes less significant when increasing the curing time at the late curing stage. The concrete microstructure is also explored to elucidate the macro-behavior of chloride migration. (C) 2017 Elsevier B.V. All rights reserved.