摘要
通过多组位移传感器和湿度传感器研究了单面干燥条件下掺与不掺粉煤灰混凝土试件距离表面不同深度处的收缩变形和相对湿度变化,并分析其相互关系。结果表明:单面干燥条件下,表层混凝土的相对湿度降低速率和收缩值明显大于内层混凝土。混凝土中收缩变形与相对湿度之间存在较好的线性关系,但在达到相同湿度时,表层混凝土收缩值小于内层混凝土。掺粉煤灰使混凝土的单位相对湿度降低引起的收缩值减小。
Shrinkage strains of high performance concrete with and without fly ash were measured in various depths from the exposed surface by using several pairs of fixed displacement sensors, and only one surface of the concrete specimen was exposed to dry condition during the experiment. Relative humidity change of concrete in various depths from the exposed surface was also studied by using embedded humidity sensors. The results show that the surface concrete shows a more reduction of relative humidity and higher shrinkage than the interior concrete when only one surface of specimen is exposed to dry condition. There is a good liear relationship between shrinkage and relative humidity in different depths of specimen for every concrete. However, the surface layer concrete has a lower shrinkage than the internal layer concrete when they reach the same relative humidity, the ratio of shrinkage value to relative humidity reduction is also decreased with the addition of fly ash.
出处
《低温建筑技术》
2009年第10期13-15,共3页
Low Temperature Architecture Technology
关键词
高性能混凝土
收缩梯度
湿度梯度
high performance concrete
shrinkage gradient
humidity gradient
