Carbonation resistance of fly ash concrete
Carbonation resistance of fly ash concrete
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DOI：
10.1680/macr.15.00204
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发表时间：
2015-01-01
影响因子：
2.7
通讯作者：
Ghataora, Gurmel S.
中科院分区：
文献类型：
--
作者：
Lye, Chao-Qun;Dhir, Ravindra K.;Ghataora, Gurmel S.
基于系统分析、评估和综合33个国家自1968年以来发表的213项研究中产生的3万份强有力的数据矩阵，本文详细介绍了已经开展的研究范围，并讨论了粉煤灰（FA）对混凝土碳化和碳化引起的腐蚀的影响。研究表明，FA作为水泥成分，如BS EN 197- 1:20 11中采用的成分，在混凝土按水灰比或强度等设计时都会增加混凝土的碳化率，尽管后者的作用程度较小。在使用中的混凝土中也证实了这种碳化的增加。FA含量对混凝土碳化的净影响取决于配合比设计、养护和暴露相关参数的组合。混凝土中的FA也被证明会增加钢筋的腐蚀，这只能通过增加钢筋覆盖层、混凝土强度或两者的结合来克服，超出了欧洲法规2、BS EN 206-1: 2013和BS 8500等标准的规定。与人们普遍持有的观点相反，本研究表明，在加速和自然二氧化碳暴露下，FA混凝土的相对碳化率与相应的波特兰水泥混凝土保持相似。
Based on systematic analysis, evaluation and synthesis of a 30 000 strong data matrix generated from 213 studies from 33 countries published since 1968, this paper details the extent of research that has been undertaken and discusses the effect of fly ash (FA) on the carbonation and carbonation-induced corrosion of concrete. It is shown that FA as a cement component, such as those adopted in BS EN 197-1: 2011, increases the carbonation rate of concrete, both when concrete is designed in terms of equal water/cement ratio or strength, though with the latter to a lesser extent. This increase in carbonation has also been confirmed for in-service concrete. The net effect of FA content on the carbonation of concrete is dependent upon the combination of mix design, curing and exposure related parameters. FA in concrete is also shown to increase the corrosion of reinforcement, which can only be overcome by increasing the cover to reinforcement, concrete strength, or a combination of the two, beyond those specified in standards such Eurocode 2, BS EN 206-1: 2013 and BS 8500. Contrary to the commonly held view, this study shows that the relative rate of carbonation of FA concrete with reference to corresponding Portland cement concrete remains similar under accelerated and natural carbon dioxide exposures.