Carbonation of concrete made with dredged marine sand and its effect on chloride binding
Carbonation of concrete made with dredged marine sand and its effect on chloride binding
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疏浚海砂混凝土的碳化及其对氯离子结合的影响
DOI：
10.1016/j.conbuildmat.2016.05.011
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发表时间：
2016-09-01
影响因子：
7.4
通讯作者：
Lo, Tommy Y.
中科院分区：
文献类型：
--
作者：
Liu, Wei;Cui, Hongzhi;Lo, Tommy Y.
为了满足建筑行业的需求，尤其是在中国，河沙 (RS) 被过度开采。疏浚海砂 (DMS) 中的氯化盐是限制 DMS 在钢筋混凝土 (RC) 结构中使用的主要问题。与 RS 混凝土相比，本文建立了 DMS 混凝土中碳化行为和氯离子之间的相互作用模型。在这项研究中，测试结果表明，DMS引入的氯离子可以减少DMS混凝土20-50%的碳化。较高的抗碳化能力可以减少混凝土中钢筋腐蚀的可能性。混凝土碳化过程可以改变混凝土中氯离子的状态及其浓度。在碳化过程中，结合的氯离子会游离出来，当氯离子浓度低于水泥质量的3%时，其在碳化混凝土中的浓度比非碳化混凝土增加高达200%。因此，当 DMS 混凝土设计用于 RC 结构时，必须考虑碳化对氯离子的影响和耐久性。 (C) 2016 Elsevier Ltd. 保留所有权利。
River sand (RS) has been overly exploited to meet demand in the construction industry, particularly in China. Chloride salt in dredged marine sand (DMS) is the primary concern that limits the use of DMS in reinforced-concrete (RC) structures. This paper developed an interaction model between the carbonation behaviour and chloride ions in DMS concrete compared with RS concrete. In this research, the test results indicated that the chloride ions introduced by DMS can reduce 20-50% carbonation of the DMS concretes. A higher carbonation resistance can reduce the possibility of steel bar corrosion in the concrete. The process of concrete carbonation can alter the state of chloride ions in the concrete and their concentrations. During the carbonation process, the bound chloride ions would become free, and their concentration in carbonated concrete could increase by up to 200% compared to that of uncarbonated concrete when the chloride ion concentration was less than 3% by cement mass. Therefore, the effect of carbonation on chloride ions must be considered with respect to the durability when DMS concrete is designed for use in RC structures. (C) 2016 Elsevier Ltd. All rights reserved.