机制砂中的石粉对水泥浆体流动性和干燥收缩的影响

Influence of crushed sand fines on fluidity and dry shrinkage of cement paste

测试了石粉种类、掺入方式、掺量对水泥浆体流动度和干燥收缩的影响规律。试验结果表明:石粉内掺,水泥浆体流动度随掺量增加,石粉外掺,水泥浆体流动度随掺量线性下降,固体颗粒减水剂匹配量是掺石粉水泥浆体流动度的关键因素;石粉减少了水泥浆体的28 d干燥收缩,但石粉外掺的情形下应留意1 d干燥收缩的剧增。

The effects of the type of stone powder,the way of mixing and the dosage of stone powder on the fluidity and shrinkage of cement paste were tested.The results show that the fluidity of cement paste added crushed sand fines replacing cement will be raise,otherwise not.The amount of water reducing agent on solid particle is the key factor of cement paste fluidity.The 28 d dry shrinkage of cement paste was decreased if the limestone powder was added.But The increase of 1 d dry shrinkage should be paid attention to in the case of stone powder.