脱硫石膏对钢渣制备碳化建材的影响

Effects of Desulfurization Gypsum on Steel Slag Preparation with Carbonized Building Materials

为了揭示脱硫石膏对钢渣基碳化建材制品性能的影响,研究了不同养护时间、脱硫石膏掺量对试件抗压强度、固碳效果的影响,以及固碳效果对试件抗压强度的影响。结果表明:①脱硫石膏与钢渣的质量比为6.25%时可显著改善钢渣基试件的强度和养护效率,水胶比为0.2,成型压强为9 MPa的试块碳化养护1 d的抗压强度达到32 MPa。②随着脱硫石膏掺量的增加,单位质量试块固碳量降低,而单位质量钢渣固碳量增大。③1 d和3d的固碳量与抗压强度基本呈正相关关系,这是由于钢渣的水化反应缓慢,对早期强度贡献不大,碳化反应对试块抗压强度尤其是早期强度起关键的促进作用。④成型压强为27 MPa的试件6 h、10 h固碳量分别达1 d固碳量的76.21%和87.54%,养护6 h的试件抗压强度超过25 MPa。因此,试块经过6 h的碳化养护就可以得到符合强度要求的碳化产品。

In order to reveal the influence of desulfurization gypsum on the properties of steel slag- based carbonized building materials,the effects of different curing time and desulfurization gypsum dosage on the compressive strength and carbon sequestration effect of the test pieces,and the effect of carbon sequestration on the compressive strength of the test pieces were studied.The results showed that:① When the mass ratio of desulfurization gypsum to steel slag is 6.25%,the strength and curing efficiency of the steel slag-based test piece are significantly improved.When the water-binder ratio is 0.2 and the moulded strength is 9 MPa,the compressive strength of the test piece reaches 32 MPa with the one day curing.② With the increasing of the amount of desulfurization gypsum,the carbon sequestration per unit mass of the test pieces decreases,while the carbon sequestration per unit mass of the steel slag increases.③ The carbon sequestration of 1 d or 3 d is basically positive correlation with the compressive strength,because the hydration reaction of steel slag is slow and does not contribute much to the early strength.The carbonization reaction is critical for the enhancement of compressive strength of the test pieces,especially the early strength.④ When the moulded strength is 27 MPa,the carbon sequestration of the specimens cured for 6 hours and 10 hours reaches 76.21% and 87.54% of the specimens carbon sequestration curing for 1 d,and the compressive strength of the specimens curing for 6 h was more than 25 MPa.Therefore,the test pieces become the carbonized products according with strength requirements after the carbonized curing for 6 h.