磷渣粉改善钢渣混凝土抗压强度及电通量

Compressive Strength and Electric Flux Improvement of Steel Slag Concrete by Phosphorus Slag Powder

为了提高钢渣的利用率,改善掺入钢渣对混凝土电通量的不利影响,通过磷渣粉与钢渣粉复掺的方式,制备了强度等级为C40的钢渣粉-磷渣粉混凝土。采用扫描电镜和压汞法等手段,研究了钢渣粉、磷渣粉单掺及复掺时对混凝土水化产物和微观结构的影响。试验结果表明:当总掺量为60%(钢渣粉与磷渣粉掺量比为2∶1)时,28 d抗压强度达到59.4 MPa,是空白组的116%,56 d电通量为1450 C,低于空白组电通量,比单掺40%钢渣粉组的电通量降低了1749 C。该复掺方式比单掺钢渣粉或磷渣粉更能减少水泥的用量。磷渣粉的掺入使钢渣粉掺量从20%左右提升到了50%,不仅提高了钢渣粉的利用率,还改善了钢渣粉掺入对混凝土抗氯离子渗透性的不利影响。

In order to improve the utilization rate of steel slag and decrease the adverse effect of the mixed steel slag on the electric flux of concrete,a steel slag and phosphorus slag powder concrete with a strength level of C40 was prepared by mixing phosphate slag powder and steel slag powder.Scanning electron microscope and mercury intrusion method were used to study the effects of steel slag powder and phosphate slag powder on the hydration products and microstructure of concrete.The experimental results show that when the total dosage is60%(the ratio of steel slag powder to phosphate slag powder is 2∶1),the 28 d compressive strength reaches to 59.4 MPa,which is 116%of the blank group.The 56 d electric flux is 1450 C,which is lower than that of the blank.Compared with the single-mixed 40%steel slag powder group,the eletric flux of the group is reduced by 1749 C.The compounding method can reduce the amount of cement compared with the singlemixed steel slag powder or phosphorus slag powder.The dope of phosphorus slag powder increases the amount of steel slag powder from about 20%to 50%,which not only improves the utilization rate of steel slag powder,but also decreases the adverse effect of the incorporation of steel slag powder on the chloride ion permeability resistance of concrete.