掺矿粉粉煤灰混凝土塑性收缩的量化研究

以掺矿粉粉煤灰泵送混凝土塑性阶段的体积减缩量作为评价泵送混凝土塑性收缩的量化依据,证实了掺用矿渣微粉与混凝土塑性收缩裂缝有一定的内在关系,尤其是夏季采用25%以上的大掺量用于现浇楼板等薄壁结构混凝土工程,极易引发混凝土塑性裂缝。通过复掺粉煤灰能显著提高泵送矿渣微粉混凝土的抗塑性收缩能力。

Taking volume decrement of blast furnace slag （BFS） and fly ash pump concrete in plastic stage as quantification basis for evaluation of pump concrete plastic shrinkage proves that plastic shrinkage crack of pump concrete has certain internal relation with adding slag micropowder.Especially using large amount of BFS over 25% for concrete project of thin wall structure in summer such as in-situ floor will easily cause concrete plastic shrinkage cracking.Adding fly ash in BFS pump concrete can significantly enhance the capability of plastic shrinkage resistance.