摘要
为了揭示粉煤灰对水泥基材料自生收缩和干燥收缩间的定性和定量关系 ,分别测定了质量分数为 0 3 0 ,0 45和 0 60的超细低钙粉煤灰或I级低钙粉煤灰砂浆从加水养护 1d至 12 0d的自生收缩 (ε1 )和干燥收缩应变值 (ε2 )。试验结果表明 ,早期 (7d内 )粉煤灰砂浆的自生收缩会比基准砂浆低 ,粉煤灰对砂浆自生收缩的作用受到粉煤灰自身活性和粉煤灰取代水泥质量分数的影响 ,粉煤灰活性高 ,其砂浆早期自身收缩大 ,后期自身收缩随粉煤灰取代水泥质量分数的增加而减小。提出的回归模型ε1 /ε2 =eat-b能够很好地反映随时间延长 ,水泥基材料自生收缩在总干燥收缩中所占的比率。
In order to reveal the qualitative and quantitative relationships between autogenous shrinkage and drying shrinkage of the cement-based materials, the autogenous shrinkage (Ε1) and drying shrinkage strain values (Ε1 and Ε2) of the mortars containing 0.30, 0.45 and 0.60 of mass fraction of superfine or grade I class F fly ash, cured from 1 day to 120 days after adding water, were measured respectively. Experimental results demonstrate that the autogenous shrinkage strain value of fly ash mortar is lower than that of reference mortar within the first seven days. The influence of fly ash on the autogenous shrinkage of the mortar is depended on the activity of the fly ash and the mass fraction of the fly ash for replacing the cement. The higher the activity of fly ash is, the larger the autogenous shrinkage of the mortar will be at the early stage. The autogenous shrinkage of the mortar at the later stage is reduced with the increase of the mass fraction of the fly ash due to the replacement of the cement. The change for the rate of autogenous shrinkage to the drying shrinkage of cement-based materials with the time extension of the cured is well illustrated by the regression model obtained.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2003年第5期428-433,共6页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金(5993 8170 )重点资助项目
华侨大学科研基金资助项目
