微膨胀自密实钢管外包混凝土性能调控及配制研究
Study on the Performance Control and Preparation of Micro-expansion and Self-compacting Concrete Coated with Steel Pipe
李宝清 1马崇珍 1曾泳太 1陈旭 1李存2
作者信息
- 1. 四川省交通建设集团有限责任公司 成都 610047
- 2. 武汉理工大学交通与物流工程学院 武汉 430063
- 折叠
摘要
随着我国工程建设质量标准的不断提高,普通混凝土在钢筋密集环境中不宜振捣的缺点也逐渐显现.四川卡哈洛金沙江大桥主塔钢管外包壁薄、钢筋密布,普通混凝土不能满足施工质量要求,因此需要通过自密实混凝土实现模板填充饱满,确保外观质量.文中以四川卡哈洛金沙江大桥工程项目为背景,探究四川卡哈洛地区自密实混凝土配合比设计,并通过平板法测定自密实混凝土的早期开裂敏感性.结果表明,添加10％掺量的CEA膨胀剂,现场应用效果较好,28 d抗压强度为39.2 MPa,提升10.7％.平均开裂面积小于10 mm2,单位面积开裂裂缝数目小于10条/m2,符合抗裂性Ⅰ级标准,满足工程质量要求.
Abstract
With the continuous improvement of construction quality standard in China,the shortcom-ings of ordinary concrete,which is not suitable for vibration in the environment of dense steel rein-forcement,have gradually appeared.The main tower of Sichuan Kahalo Jinsha River Bridge has a thin wall of steel pipe wrapping and dense reinforcement,and ordinary concrete cannot meet the construc-tion quality requirements,so it is necessary to realize full filling of the formwork through self-compac-ting concrete to ensure the appearance quality.Based on the background of Sichuan Kahalo Jinsha Riv-er Bridge project,the design of self-compacting concrete proportion was explored,and the early crack-ing susceptibility of self-compacting concrete was determined by using the flat-plate method.The re-sults show that adding 10％CEA expansion agent,the field application effect is better,and the 28 day compressive strength is 39.2 MPa with an increase of 10.7％.The average cracking area is less than 10 mm2,the number of cracks per unit area is less than 10,which meets the Class Ⅰ crack resistance standard and the engineering quality requirements.
关键词
微膨胀自密实混凝土/配合比设计/CEA膨胀剂/早期开裂Key words
micro-expansion self-compacting concrete/mixing ratio design/CEA expansion agent/early cracking引用本文复制引用
出版年
2024
NETL
NSTL
万方数据