混凝土抗裂能力评价模型的解析  

Analysis on the Evaluation Model of Anti-Cracking Ability of Concrete

作　　者：王迎飞[1] 周丽美[1] 李超[1] 张夏虹[1] 

机构地区：[1]中交四航工程研究院有限公司中交集团建筑材料重点实验室交通行业水工构造物耐久性技术重点实验室,广东广州510230

出　　处：《中国港湾建设》2009年第1期13-17,共5页China Harbour Engineering

摘　　要：综述了目前国内外混凝土抗裂能力评价计算模型,通过综合各方面影响因素,首次建立了混凝土抗裂能力分析模型,并考虑混凝土的经时变化,创建混凝土及其结构抗裂能力评价模型,用抗裂因子Kac作为评价混凝土抗裂能力的数学参数。选择具有代表性的混凝土配合比,分别计算了粉煤灰、矿渣、硅灰、膨胀剂、减缩剂、聚丙烯纤维组分的抗裂因子,通过数学计算得出的抗裂因子的大小顺序表明:粉煤灰、矿渣能够提高混凝土的抗裂因子,而硅灰则降低了混凝土的抗裂因子。掺加纤维、减缩剂、以及减缩剂和膨胀剂复合使用能够提高混凝土的抗裂性能,特别是减缩剂和膨胀剂复合使用能够大幅度提高抗裂因子,与大小圆环、平板法等各种约束开裂试验结果具有很好的一致性。而使用膨胀剂在早期养护不充分的前提下,有降低抗裂因子的趋势。This paper summarizes the calculation and evaluation model of anti-cracking ability of concrete at home and abroad. Through synthesizing the relevant factors, analysis model of anti-cracking ability of concrete is established for the first time, and meanwhile, considering the time-change of concrete, evaluation model of anti-cracking of concrete and its structure are es- tablished, and adopting Kao as mathematical parameter on anti-cracking performance of concrete. Choose representative con- crete mixture, proportions, such as flying ash, blast furnace stag, silica fume, expansion agent, shrinkage-reducing agent, Polypropylene fibre etc. Kac of them are calculated respectively. It is concluded that FA, slag, fibre, SRA and SRA＋EA can improve anti-cracking performance, but silica fume can decrease anti-cracking performance by comparison on K~, and among them, whiling to use shrinkage-reducing agent and expansion agent with combination can promote effectively anti-cracking performance of concrete. The calculation results of/Ca c are in according with that of restraint-cracking experiments such as big-small steel rings, flat-restraint. However, if the early curing of concrete is inadequate by using expansion agents, the trend of K~ maybe reduced.

关 键 词：混凝土 收缩开裂 约束开裂试验 抗裂能力评价模型 抗裂因子 

分 类 号：TU528[建筑科学—建筑技术科学]