重构钢渣复合硅酸盐水泥的水化性能及抗硫酸盐侵蚀性能研究

Study on hydration performance and sulfate corrosion resistance of reconstituted steel slag composite Portland cement

针对钢渣的成分特点,以石灰和铝矾土作为调质组分对钢渣进行物相重构,制备以C_(2)S、C_(4)AF为主要矿物的重构钢渣,将其按不同比例(10%、20%、30%、40%)与硅酸盐水泥复合制备高铁低钙硅酸盐水泥,重点研究重构钢渣掺量对水泥力学性能、水化活性及抗硫酸盐性能的影响。研究结果表明:重构钢渣的掺入降低了水泥标准稠度用水量,延长了凝结时间;重构钢渣复合水泥具有后期强度增长快的特点,掺量小于30%时28 d活性指数均超过100%;掺入重构钢渣能显著降低水泥的早期水化热,掺量为30%的水泥放热总量为254 J/g,比纯水泥低了18.3%;铁相在水化过程中,部分Fe取代水化产物中的Al,与SO_(4)^(2-)形成膨胀性小的富铁钙矾石,填充孔隙结构,提升其抗硫酸盐侵蚀性能。

According to the composition characteristics of steel slag,lime and bauxite were used as conditioning and tempering components to reconstruct the phase of steel slag,and the reconstruction steel slag mainly composed of C_(2)S and C_(4)AF was prepared.The high iron and low calcium Portland cement was prepared by compounding the steel slag with Portland cement in different proportions(10%,20%,30%,40%).The key research is the influence of reconstruction steel slag content on mechanical properties,hydration activity and sulfate resistance of cement.The results show that the addition of reconstructed steel slag reduces the water consumption for standard consistency of cement and prolonging the setting time.The strength of reconstructed steel slag composite cement increased rapidly in the later period,and the activity index of 28 d was more than 100%when the dosage was less than 30%.Adding reconstructed steel slag can significantly reduce the early hydration heat of cement,and the total heat release of cement with the content of 30%is 254 J/g,18.3%lower than that of pure cement.In the hydration process of iron phase,part of Fe replaces Al in hydration products and forms iron-rich ettringite with SO_(4)^(2-) to fill pore structure and improve its resistance to sulfate erosion.