超高性能混凝土基体中氯离子结合特性的研究  

Study of chloride binding property in ultra high performance concrete matrix

作　　者：黄政宇[1] 李涛[1] 

机构地区：[1]湖南大学土木工程学院,湖南长沙410082

出　　处：《铁道科学与工程学报》2016年第10期1912-1918,共7页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(U1305245)

摘　　要：从测试方法、养护条件、氯离子含量、掺合料品种等方面研究采用模拟海水拌合的超高性能混凝土基体氯离子的结合特性。试验结果表明:由于高温使UHPC基体中Friedel盐分解,试样干燥温度为100℃时的自由氯离子含量比50℃的高;早期高温湿养降低了最终UHPC基体中氯离子的结合;随着龄期的增长,氯离子的结合逐渐增大;且氯离子的含量越高,氯离子的结合度也越大;掺合料的组成方面,硅灰的加入降低了C-S-H凝胶的钙硅比值及基体的p H值、稀释了铝酸三钙而降低UHPC基体中氯离子的结合;粉煤灰中较高含量的氧化铝促进了UHPC基体中氯离子的结合;偏高岭土富含的氧化铝与氯离子可以加速反应生成Friedel盐,从而促进UHPC基体中氯离子的结合。The paper studied the binding property of chloride in ultra high performance concrete matrix which was mixed with simulate seawater from test method, curing condition, chloride content, and admixture composi-tion. The result shows：High temperature decomposed the Friedel salt and final the free chloride content at 100 degree was higher than that at 50 in sample. Early high temperature humidity curing will reduce the final chloride binding. However, with the increase of age, the chloride binding will increase gradually. The more chloride is added, the greater the degree of chloride binding. For the composition of admixture, the addition of silica fume will lead to decreased of the calcium silicon ratio of C-S-H gel and the pH value. Meanwile, it will also cause the dilution of three calcium because of the decrease of chloride binding in UHPC matrix. The higher alumina content in fly ash promotes the chloride binding in UHPC. For metakaolin, the chloride can accelerate the forma-tion of Friedel salt which can promotes the chloride binding in UHPC matrix.

关 键 词：超高性能混凝土基体 氯离子结合 硅灰 粉煤灰 偏高岭土 

分 类 号：TU528[建筑科学—建筑技术科学]