| 摘要: |
| 为合理评价钢筋混凝土腐蚀的氯离子含量，阐明碳化与氯盐复合作用下钢筋腐蚀的真实机理，研究了碳化对水泥石内氯离子分布的影响.结果表明：碳化作用下含氯盐水泥石非碳化区Friedel复盐衍射峰大量存在，而碳化区未见Friedel复盐衍射峰；碳化过程中Friedel复盐分解后产生的氯离子向非碳化区迁移和浓缩，氯离子在碳化区浓度降低，在碳化界面则明显升高.氯盐含量为10%（质量分数）的水泥石在碳化之前的氯离子分布比较均匀，其相对浓度峰值为68，碳化2周后峰值为151，碳化4周时峰值达到298，说明碳化与氯盐复合作用会显著降低钢筋腐蚀的初始氯离子含量，提高碳化界面的钢筋腐蚀概率，加快钢筋腐蚀速度. |
| 关键词: 碳化 氯离子 复合作用 离子迁移 |
| DOI：103969/jissn1007 9629201501020 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51278255,51478227）；浙江省自然科学基金资助项目（LY12E08006）；宁波市重大科技计划项目（2013C51006） |
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| Effects of Carbonation on Chloride Ion Distribution in Hardened Cement Concrete |
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LIU Junzhe, YAN Jiali, BA Mingfang, HE Zhimin, CHEN Jianbin
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Faculty of Architectural, Civil Engineering and Environment, Ningbo University, Ningbo 315211, China
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| Abstract: |
| In order to reasonably evaluate the contents of chloride ion for reinforced concrete corrosion, effects of carbonation on chloride ion concentration distribution inside hardened cement paste were investigated and the corrosion characteristics of reinforced concrete under the combined action of carbonation and chloride were clarified. The results show that under carbonation Friedel salt diffraction peaks abound in non carbonation zone of hardened cement paste containing chloride while this kind of diffraction peaks could not be found in carbonated zone. During carbonation process the chloride ion from decomposition of Friedel salt migrates to the non carbonation area and accumulated, chloride ion concentration deceases in carbonation zone and significantly increases in carbonation interface; chloride ion distribution in hardened cement paste containing 10% chloride ion is relatively uniform before carbonation and its relative concentration peak value is 68. After two weeks carbonation, the maximum peak value becomes 151 and four weeks carbonation later this value reaches 298. Thus the combined action of carbonation and chloride salt increasingly reduces the initial critical chloride ion concentration for reinforced concrete corrosion and increases the chance of steel corrosion in carbonation frontier, thus steel corrosion rate is accelerated. |
| Key words: carbonation chloride ion combined action migration of ion |
