钢渣粉对硫铝酸盐水泥水化过程的影响及热力学模拟

通过测试水泥浆体的凝结时间、抗压强度、电阻率,同时结合水化产物分析及热力学模拟,研究了不同掺量钢渣粉对硫铝酸盐水泥水化行为的影响规律。结果表明,随着钢渣粉质量掺量的增大,初凝时间呈先延长后缩短的趋势,且在掺量为20%时达到最大值。在28 d龄期内,掺入钢渣粉的水泥硬化浆体抗压强度均小于未掺入钢渣粉的硬化浆体,但在龄期达到60 d和90 d时,掺入40%钢渣粉试样的抗压强度均大于未掺入钢渣粉的试样。钢渣粉与硫铝酸盐水泥复合浆体的电阻率在水化初始阶段随着钢渣粉掺量的增大而增大,在水化后期(约3 h后)则随钢渣粉掺量的增大而减小。在1 d龄期内,钢渣粉掺量为40%的试样中的钢渣粉发生了水化反应,使得水泥浆体在减速期的水化速率最大。由热力学模拟结果可知:在钢渣粉掺量为40%的试样中,C₂S在10 h后开始进行水化反应,C₂ASH₈则在168 h后开始生成;当钢渣掺量大于15%时,随着钢渣粉掺量的增大,钙矾石和铝胶的生成量逐渐减少,C₂ASH₈的生成量逐渐增多。

Effect of Steel Slag Powder on Hydration Process of Calcium Sulfoaluminate Cement and Thermodynamic Modelling

The influence of variable steel slag powder content on the hydration behavior of calcim sulfoaluminate cement was investigated through the setting time test, compressive strength test and electrical resistivity test, combined with hydration products analysis and thermodynamic modelling. The results show that with the increase of the mass content of steel slag powder, the initial setting time shows a trend of first extending and then shortening, and reaches the maximum when the content of steel slag is 20%. In 28 d, the compressive strength of cement paste with steel slag powder is lower than the hardened paste without steel slag powder, but at the age of 60 d and 90 d, the compressive strength of cement paste with 40% steel slag powder content is higher than the sample without steel slag powder. The resistivity of steel slag powder and calcium sulfoaluminate cement composite paste increases with the increase of steel slag powder content in the initial hydration stage, and decreases with the increase of steel slag powder content in the late hydration stage (after about 3 h). In the age of 1 d, the hydration reaction of steel slag powder occurs in the sample with 40% steel slag powder content, which makes the hydration rate of cement paste reach the maximum in the deceleration period. According to thermodynamic modelling results, in the sample mixes with 40% steel slag powder, C₂S began to react after 10 h, forming C₂ASH₈ after 168 h. When the steel slag content is more than 15%, with the increase of the steel slag powder content, the production of ettringite and AH₃ gradually decreases, and the production of C₂ASH₈ gradually increases.