摘要
早期开裂是当前混凝土施工应用中经常出现的质量通病,采取什么样的措施防止这种开裂成为当前研究热点.就掺入聚丙烯纤维、碳纤维、减缩剂及复合使用时混凝土的早期开裂、自收缩、抗渗性等进行了试验研究,并从扫描电镜照片进行微观结构分析.结果表明:纤维或减缩剂的加入都对混凝土早期开裂有一定抑制作用,但对混凝土抗压强度有一定降低.从综合性能看,各种措施对防止混凝土早期开裂的效果优劣次序为:减缩剂>减缩剂+聚丙烯纤维>碳纤维>聚丙烯纤维.
Early age cracking is a kind of common faults that occur during concrete constructions,how to avoid this kind of cracking becomes one research focus at present.Early age cracking,autogenous shrinkage and impermeability of concretes containing polypropylene fibre,carbon fibre and shrinkage reducing agent solely or coherently are studied in this paper.And the microstructures of concretes are analyzed through SEM photos.The results show that fibres added or shrinkage reducing agent can prevent concretes from cracking at early age to a certain extent,but decrease the compressive strength of concrete more or less.When the effects of different measures for avoid early age cracking are valuated from the general performance,the following order from high to low is obtained:shrinkage reducing agent,shrinkage reducing agent plus polypropylene fibre,carbon fibre and polypropylene fibre.
出处
《哈尔滨建筑大学学报》
北大核心
2002年第5期77-80,共4页
Journal of Harbin University of Civil Engineering and Architecture
基金
国家自然科学基金资助项目(50078019)
关键词
高性能混凝土
早期开裂
自收缩
抗渗性
显微结构
防止
HPC
early age cracking
autogenous shrinkage
impermeability
counter measures
microstructrue
