矿物掺合料的颗粒级配对混凝土强度的影响(Ⅱ)——矿物掺合料级配优化对混凝土强度的影响

The effect of grain composition of mineral mixture on concrete strength (Ⅱ) —The effect of the optimization of gradation of mineral mixture on concrete strength

通过粗细不同的粉煤灰、钢渣和矿渣按5:3:2(质量比)混合并以之替代50%水泥制备混凝土并对其进行性能研究。表明粉煤灰、钢渣和矿渣之间存在着一个最佳的颗粒级配体系。通过3种矿物掺合料级配复合,可以将粉煤灰、钢渣等低活性工业废渣高比例引入混凝土的制备过程中,同时使混凝土的早期强度特别是7d抗压强度显著提高,使含50%矿物掺合料的混凝土达到C40强度等级。另外,由于矿物掺合料的级配优化使混凝土的密实度明显提高,混凝土浆体中有害孔的数量明显减少,混凝土的孔结构因此得到改善。

Different finess of fly ash, steel slag and slag were mixed as the proportion of 5：2：3, and 50% of them replaced cement to make concrete and the properties of concrete were studied. The study showed there was an optimal grain composition among fly ash, slag and steel slag particles. By the composition of these three mineral mixtures, low activity industrial residue such as fly ash and steel slag can be introduced into the concrete manufacture in a very large dosage. The early strength especially the 7d compressive strength of concrete was remarkably enhanced, which made the concrete containing 50% mineral admixture reach the grade of C40. In addition ,the compactness of concrete was enhanced obviously because of the optimization of gradation of mineral admixture. The volume of harmful pores of concrete slurry was decreased. As a result, the pore structure of concrete was improved.