无约束多条件下钢渣水泥砂浆的长期干缩性能

工业钢渣中含有部分C₂S、C₃S等矿物,具有与水泥熟料相似的胶凝性能,但因其含有一定量的f-CaO和f-MgO,掺量过大易引起安定性不良。为了更好地将钢渣细集料应用到水泥砂浆中,采用水泥胶砂干缩试验,研究其在不同养护条件及不同龄期下对水泥砂浆长期干缩性能的影响。试验结果表明:在标准养护条件下,单掺钢渣粉60%和单掺钢渣砂70%时,钢渣水泥砂浆的干缩率最小。复掺钢渣粉与钢渣砂时,观察到掺量控制在钢渣粉20%、钢渣砂40%和钢渣粉30%、钢渣砂60%时,钢渣水泥砂浆的干缩率最小。在恒温养护条件下,单掺钢渣粉35%与单掺钢渣砂40%时,水泥砂浆的长期干缩值最小。

Long-term Drying Shrinkage Performance of Steel Slag Cement Mortar under Unconstrained Multi-condition

Industrial steel slag can be used as an additive in concrete as it contains such minerals as C₂S and C₃S which have similar gelling properties with cement clinker. Nevertheless, excessive dosage of industrial steel slag would result in inferior stability because it also contains f-CaO and f-MgO. To better utilize fine aggregate of steel slag in cement mortar, we performed drying shrinkage test to investigate the influence of steel slag on the long-term drying shrinkage performance of cement mortar at different curing ages under different curing conditions. Test results demonstrated that under standard curing condition, the drying shrinkage rate of cement mortar reached the lowest when added with 60% single steel slag powder, or 70% single steel slag sand, or 20% powder mixed with 40% sand, or 30% powder mixed with 60% sand; under constant temperature curing condition, the long-term dry shrinkage value of cement mortar was the lowest when 35% of steel slag powder was mixed with 40% steel slag sand.