摘要
为了研究氧化镁膨胀剂与水化热调控剂复掺对混凝土抗裂性能的影响,探讨水化热调控剂的作用机理,开展了单掺氧化镁及水化热调控剂与氧化镁复掺对混凝土水化热、绝热温升、限制膨胀率、体积变形、自收缩、弹性模量及微观结构的影响研究。结果表明:水化热调控剂可显著改变水泥水化放热历程,净浆抑温率可达31.2%,随入模温度升高,抑温效果增强;水化热调控剂可激发氧化镁的水化,促进膨胀能的释放,随养护温度提升,作用效果更显著;水化热调控剂可改变混凝土温升历程,特别是降低混凝土早期水化热释放速率;水化热调控剂与氧化镁复掺可降低混凝土自收缩,当水化热调控剂掺量为0.2%和0.4%(质量分数)时,混凝土收缩值分别减少了84με和54με;水化热调控剂会导致混凝土早龄期弹性模量降低,但对长龄期弹性模量影响不大;水化热调控剂对水泥水化历程、水化产物生成及微观结构密实程度的改变是提高混凝土抗裂性能的根本原因。
In order to study the effect of magnesium oxide expansion agent and hydration heat regulator compounding on the crack resistance of concrete and explore the mechanism of hydration heat regulator, diabetic temperature rise, limited expansion rate, volume deformation, self-shrinkage, elastic modulus of the concrete mixed with magnesium oxide and the concrete mixed with magnesium oxide and hydration heat regulator were tested, and the microstructure was investigated. The results show that the hydration heat regulator can significantly change the cement hydration exothermic process, the temperature suppression rate of the slurry reaches 31.2%, and the temperature suppression effect is enhanced with the increase of the mold temperature. The hydration heat regulator can stimulate the hydration of magnesium oxide and promote the release of expansion energy, and the effect is more obvious with the increase of curing temperature. The hydration heat regulator can change the temperature rise history of concrete, especially reduce the early hydration heat release rate. The combination of hydration heat regulator and magnesium oxide can reduce the self-shrinkage of concrete. When the content of hydration heat regulator is 0.2% and 0.4%(mass fraction), the shrinkage value is reduced by 84 με and 54 με, respectively. The hydration heat regulator will reduce the elastic modulus of concrete in the early age, but it has little effect on the elastic modulus in the long age. The change of cement hydration process, hydration product generation and microstructure compactness caused by hydration heat regulator is the fundamental reason for improving the crack resistance of concrete.
作者
程福星
张珍杰
周月霞
辜振睿
向飞
王海龙
纪宪坤
CHENG Fuxing;ZHANG Zhenjie;ZHOU Yuexia;GU Zhenrui;XIANG Fei;WANG Hailong;JI Xiankun(Wuhan Ujoin Building Material Technology Co.Ltd.,Wuhan 430083,China;Wuhan Sanyuan Special Building Material Co.Ltd.,Wuhan 430083,China)
出处
《硅酸盐通报》
CAS
北大核心
2022年第12期4273-4281,共9页
Bulletin of the Chinese Ceramic Society
基金
2021年度湖北省建设科技计划(2021-55)。
关键词
水化热调控剂
氧化镁
抗裂
绝热温升
弹性模量
自收缩
hydration heat regulator
magnesium oxide
crack resistance
adiabatic temperature rise
elastic modulus
self-shrinkage
