Influence of carbonation on chloride penetration of pastes under cyclic wetting–drying conditions
Influence of carbonation on chloride penetration of pastes under cyclic wetting–drying conditions
复制标题
循环润湿干燥条件下碳化对糊剂氯化物渗透的影响
DOI：
10.1680/jadcr.19.00047
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发表时间：
2019-12
影响因子：
2
通讯作者：
Xuan Zhang
中科院分区：
文献类型：
--
作者：
Honglei Chang;Jian Liu;Sen Cheng;Xuan Zhang
在循环干湿氯离子侵蚀环境下，碳酸化对于氯离子传输具有重要意义。在这项工作中，通过将普通水泥浆体样本和具有不同水/粘合剂比例和矿物掺合料的预碳酸化浆体样本暴露在相同的循环润湿-干燥条件下，研究了碳化对氯化物渗透率的影响。研究发现，更致密的孔隙结构或更高的氯离子结合能力可以减缓氯离子的渗透。因此，氯离子渗透速率取决于孔隙结构和氯离子结合能力的组合，孔隙结构决定了水泥浆体的一般渗透性。然而，无论孔隙结构如何，碳酸化更有可能加速氯离子渗透，因为碳酸化导致氯离子结合能力大幅下降。
Under a cyclic wetting–drying chloride attack environment, carbonation is of great significance for chloride transport. In this work the impact of carbonation on the chloride penetration rate was investigated by exposing normal cement paste specimens and pre-carbonated paste specimens with different water/binder ratios and mineral admixtures to the same cyclic wetting–drying conditions. It was found that either a denser pore structure or a higher chloride binding capacity can slow down chloride penetration. The chloride penetration rate thus depends on the combination of the pore structure, which determines the general permeability of cement pastes, and the chloride binding capacity. However, carbonation is more likely to accelerate chloride penetration regardless of the pore structure, due to the overwhelming decrease in the chloride binding capacity as a result of carbonation.