硫酸亚铁对铝酸盐水泥浆体性能及水化产物的影响

Effect of Ferrous Sulfate on Properties and Hydration Products of Aluminate Cement Paste

铁相对水泥混凝土耐久性具有显著的积极作用,为拓宽铁相来源,本文研究了铁盐对铝酸盐水泥性能及水化产物的影响。通过将铝酸盐水泥和硫酸盐(二水石膏和硫酸亚铁)复合,使铝酸盐水泥水化生成以钙矾石为主的产物,在此基础上,研究了硫酸盐中硫酸亚铁比例对铝酸盐水泥浆体凝结时间、抗压强度以及体积稳定性的影响规律,并采用XRD和SEM分析水化产物类型以及微观形貌,阐明硫酸亚铁对水泥浆体性能的影响机理。结果表明:适量的硫酸盐可提升铝酸盐水泥浆体的抗压强度;硫酸亚铁对铝酸盐水泥表现出轻微的促凝作用,对膨胀率具有显著的抑制作用;硫酸亚铁对钙矾石的形成具有明显的抑制作用,适量的硫酸亚铁使得所生成的钙矾石尺寸较小,且分布均匀,有利于提升硬化浆体的抗压强度。

Iron phase has a significant positive effect on the durability of cement concrete.In order to broaden the sources of iron phase,the effects of iron salts on the properties and hydration products of aluminate cement were studied.The combination of aluminate cement and sulfate(gypsum and ferrous sulfate)was used to form ettringite as a main hydration product of aluminate cement.Then,the influence of the proportion of ferrous sulfate in sulfate on the setting time,compressive strength and volume stability of aluminate cement paste was studied.The type and microstructure of the hydration products were also analyzed by XRD and SEM to reveal the influence mechanism of ferrous sulfate on properties of cement paste.The results show that appropriate amount of sulfate can improve the compressive strength of aluminate cement paste.Ferrous sulfate has a slight promoting effect on the setting time and a significant inhibiting effect on the expansion rate of aluminate cement.Ferrous sulfate inhibits the formation of ettringite,and an appropriate amount of ferrous sulfate makes the generated ettringite with smaller size and uniform distribution,which is conducive to improving the compressive strength of the hardened paste.