摘要
以国标Ⅱ型高效膨胀剂为研究对象,系统研究了补偿收缩混凝土中砂率和砂种类等参数引起的混凝土内约束变化对膨胀剂膨胀效能发挥的影响规律。结果表明:随着砂率增大,骨料对膨胀剂内约束作用减弱,利于膨胀剂膨胀效能的发挥,相应的增大了补偿收缩混凝土水养膨胀变形;砂率增大也降低了骨料对水泥浆体收缩应力的约束作用,密封绝湿养护环境下,补偿收缩混凝土自生体积变形随砂率变化表现出先增大后减小趋势;与天然河砂相比,人工砂棱角多,对膨胀剂内约束作用大,相应的降低了膨胀剂在补偿收缩混凝土中水养膨胀变形和自生体积变形。
Taking the national standard type II high-efficiency expansion agent as the research object,the influence of the change of concrete internal constraints caused by the parameters such as sand rate and sand type in compensating shrinkage concrete on the expansion efficiency of the expansion agent was systematically studied.The results show that with the increase of sand rate,the internal restraint effect of aggregate on the expansion agent is weakened,which is conducive to the expansion efficiency of the expansion agent,and the water-nutrient expansion and deformation of the compensated shrinkage concrete is increased accordingly.The increase of sand rate also reduces the restraining effect of aggregate on the shrinkage stress of cement slurry,and the spontaneous volume deformation of compensated shrinkage concrete increases first and then decreases with the change of sand rate under the sealed moisture insulation curing environment.Compared with natural river sand,artificial sand has more edges and corners,which has a great effect on the internal restraint of the expansion agent,and correspondingly reduces the hydrotrophic expansion deformation and self-generated volume deformation of the expansion agent in compensating for shrinkage concrete.
出处
《江苏建材》
2025年第1期54-57,共4页
Jiangsu Building Materials
关键词
内约束
膨胀剂
补偿收缩混凝土
变形特性
internal constraints
bulking agents
compensating shrinkage concrete
deformation characteristics
