硫酸钠激发钢渣粉活性改良水泥土试验研究

Experimental Study on Sodium Sulfate Exciting Steel Slag Power Activity and Improving Cement Soil

钢渣是钢铁冶炼中产生的固体废弃物;其矿物组成以硅酸盐相为主,具有潜在的胶凝性质。利用钢渣和水泥混合改良淤泥质土具有很好的研究意义,不仅可以充分利用现在仍然是废物的钢渣材料,对环境改良做出贡献;同时可以代替部分水泥,节约资源。但钢渣的活性较低导致其早期强度难以发挥。采用Na_2SO_4作为激发剂,与钢渣粉混合使用以激发其活性,使得早期强度能达到工程要求。进行无侧限抗压强度试验(UCS)及X射线衍射试验(XRD),试验结果表明,在掺加Na_2SO_4试剂后,钢渣粉-水泥-淤泥土早期强度得到大幅度提升;龄期为7 d时,其强度与未掺Na_2SO_4试剂龄期28 d的强度相当;说明Na_2SO_4的掺入对早期强度有明显的改良作用。通过XRD进行物相检索,结果表明,激发剂的加入促进了钢渣-水泥的水化过程以及Ca(OH)_2,CaSO_4等水化产物的生成。

Steel slag is a kind of solid waste generated in iron and steel smelting. It has a potential gelling properties because its mineral composition is mainly composed of silicate facies. It is very useful to improve silt performance with mixture of cement and steel slag. It can not only make full use of steel slag material which is still the waste now to contribute to environmental improvement,and can replace part of the cement to save resources. But the low activity of steel slag leads the early strength difficult to play. The chemical excitations method which has been studied before was used. Using of Na2SO4 as a stimulant,mixing with steel slag to stimulate its activity,making the early strength to meet the engineering requirements. The unconfined compressive strength( UCS) test and X-ray diffraction( XRD) test use were used to analyze the effect. The results show that the strength of cement-soil is greatly improved after the addition of Na2SO4 reagent. When cured for 7 days,the strength of steel slag-cement soil with Na2SO4 has reached basically at that in 28 days without Na2SO4. It indicates that the incorporation of Na2SO4 has obvious improvement on the early strength. The materials are analyzed by XRD test,and it is found that the addition of activator has the function to promote the hydration process of steel slag-cement and promote the formation of hydration products such as Ca(OH)2 and CaSO4. It is provided that the ideas and experiences for application of steel slag in soft foundation treatment.