钢渣粉掺入对高强尾矿混凝土性能的影响

Effect of Steel Slag Powder Addition on Properties of High Strength Tailings Concrete

为了研究钢渣粉掺入对高强尾矿混凝土性能的影响,以比表面积为5 950 cm2/g的钢渣粉等量替代比表面积为5 137 cm2/g的基础胶凝材料(铁尾矿、矿渣、水泥熟料、天然石膏的梯级磨矿产品,各对应成分的质量比为40∶26∶26∶8)进行了胶砂流动度试验,并以等质量的原始粒级铁尾矿为骨料,进行了混凝土试件强度试验。结果表明:钢渣粉的掺入在一定程度上提高了体系的流动度;钢渣粉的掺入对混凝土早期强度有明显的负面影响;钢渣粉水化作用的缓慢、持久释放,使掺钢渣粉的混凝土后期强度显著增长,但钢渣粉的掺量不宜超过20%。试验产品的SEM分析表明,无论是否掺加钢渣粉,尾矿混凝土水化产物均为钙矾石和C-S-H凝胶;在反应的中后期,体系中C-S-H凝胶和钙矾石的协同生成能够促进体系强度的增长。

In order to study the effect of dosage of steel slag powder on high strength tailings concrete, the fluidity of ce- mentitious concrete strength is conducted using steel slag powder, with specific surface area of 5 950 cm^2/g, to replace the same amount of basic cementitious material,with specific surface area of 5 137 cm^2/g,which is prepared by cascade grinding products with iron tailings, slag, cement clinker and natural gypsum in proportion of 40： 26： 26： 8, and then the original iron railings as aggregate with equal quality, the concrete strength are tested. The results show that, addition of steel slag powder im- proved the fluidity of the system to some extent, and had a negative effect on the strength of concrete at early stage. That hydra- tion of steel slag power acts slowly and releases sustainably made the strength of concrete increased significantly later, while the dosage of steel slag powder should not exceed 20%. The SEM analysis on the products shows that, whether mixed with steel slag powder or not, the tailings concrete has hydration products of ettringite and C-S-H gel, during the middle and later stage of the hardening process, the coordinated growth of C-S-H gel and ettringite can increase the strength of the system.