Study on the Effect of Ash-Slag Ratio on Mechanical Properties of Magnesium Slag Cementitious Material

Abstract

Magnesium slag is a kind of industrial waste slag with silicate mineral as the main component when smelting magnesium metal. Its main component is similar to Portland cement clinker and can be used as cementitious material. In this paper, the mechanical properties of magnesia slag cementitious materials under different ash-slag ratios are studied and analysed. Magnesium slag and fly ash are prepared by composite method. The flexural and compressive tests are carried out. The effects of different ash-slag ratios on the mechanical properties of magnesia slag cementitious materials are studied. The experimental data are analysed and theoretical studies are carried out, and the conclusion is drawn on: (1) When the ash-slag ratio is between 0.43 and 0.8, the forming effect of Mg-slag cementitious material specimen is better; (2) When the ash-slag ratio changes from large to small, the properties of Mg-slag cementitious material will change greatly, from curable to powdered after curing, unable to form, and the critical value of the ash-slag ratio is between 0.25 and 0.43; (3) When the ash-slag ratio is in the range of 0.43-1.2, the mechanical strength of magnesium slag cementitious material is higher, the maximum flexural strength can reach 10 MPa, and the maximum compressive strength can reach 50 MPa.