石粉对低强度自密实混凝土性能的影响

摘要

研究了复掺石粉和粉煤灰情况下，石粉对低强度自密实混凝土性能的影响。结果表明：石粉可有效改善混凝土的和易性，但对流动性的改善效果差于粉煤灰。混凝土水化前期（7）时石粉在混凝土中的填充效应表现出类似粉煤灰的“活性”，混凝土的强度受粉煤灰和石粉掺量比率变化不大。水化后期（28～60d），石粉对强度的贡献不足，随着石粉掺量的增加强度下降。石粉起到改善混凝土早期自由收缩的作用。随着石粉掺量的增加，粉煤灰掺量的减小，混凝土自由收缩逐渐减小。%It investigated the effect of slate powder on the properties of low strength self -compacting concrete on the mixing condition.The results indicate that the slate powder can effectively improve the workability of SCC,but the effect on the improvement of liq-uidity is worse than fly ash.In the early hydration(7d),the strength had little impact by the ratio of fly ash and slate powder,for the filling effect of slate powder.In the latter hy-dration,the strength decreased with the increase of slate powder.And the slate powder can improve the early free shrinkage,with the increase of stone powder content early free shrinkage decreased.