关键词: 粉煤灰, 矿渣微粉, 初始开裂时间, 自收缩, 裂缝宽度, 干缩

Abstract: Shrinkage and cracking are the primary factors influencing the durability of modern concrete. In order to evaluate the effect of the mineral admixtures on the concrete shrinkage and cracking properities, a lot of tests were conducted by the ring test method and shrinkage experiment. The ring test method mainly reflects the resistance to drying shrinkage stress under the restraining conditions. The shrinkage test mainly reflects the volume deformation. The experimental results show as follows: Slag could inhibit the cracking of concrete within the range of certain proportion. With the increase of slag proportion the selfshrinking of concrete increases, but the drying shrinkage of concrete decreases. Flyash could effectively inhibit the cracking of concrete, with the increase of flyash proportion the concrete cracking could be effectively inhibited. With the increase of? flyash ?proportion the selfshrinking of concrete decreases, but the drying shrinkage of concrete would increase. As a whole, the flyash could effectively control the concrete shrinkage and cracking.