摘要
为了研究粉煤灰对混凝土收缩性能的影响并有效预测粉煤灰混凝土收缩发展的规律,对采用不同等级粉煤灰,且掺量分别为35%、40%、45%的粉煤灰混凝土的干燥收缩性能进行了研究,测试了各试件7-120d的收缩值.结果表明：大掺量粉煤灰对混凝土的收缩有较好的抑制作用,且对后期收缩的抑制更为显著;Ⅰ级粉煤灰对混凝土收缩的抑制效果明显优于Ⅱ级粉煤灰.对收缩的时程曲线进行分析,发现其呈复合指数关系,并给出了考虑粉煤灰掺量影响的混凝土干燥收缩预测公式.
In order to investigate the influence of fly ash on shrinkage of concrete and to effectively predict the shrinkage law of fly ash concrete, a series of experiments were carded out to evaluate the compressive strength and particularly the shrinkage properties of concrete containing high volume of fly ash. The Portland cement in concrete specimens were replaced partially by Class Ⅰ or Class Ⅱ fly ash with the replacement percentage of 35%, 40% and 45% in mass of total cementitious materials. The shrinkage of the specimens from hydration ages of 7 to 120 days were recorded. The results show that high volume fly ash markedly reduces the drying shrinkage of concrete, especially at the later ages. The effect of Class Ⅰ fly ash on reducing concrete shrinkage is superior to Class Ⅱ. By analysing the shrinkage vs time curves, a compound exponential formula is presented to predict the shrinkage of fly ash concrete. The fly ash replacement percentage is regarded as a parameter in the formula.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2007年第2期334-338,共5页
Journal of Southeast University：Natural Science Edition
基金
江苏省重大工程资助项目(STDQ-04HT20SY-010)
关键词
粉煤灰混凝土
干燥收缩
预测
收缩公式
fly ash concrete
drying shrinkage
predict
shrinkage formula
