γ-C_2S和β-C_2S的碳化与水化活性研究

Carbonation and Hydration Activity of γ-C_2S and β-C_2S

在常温常压下,γ-C_2S的水化活性很低,β-C_2S的水化活性相对较高;但在一定湿度和二氧化碳浓度下,γ-C_2S与β-C_2S都能快速地发生碳化反应。作者在实验室条件下制备了纯的γ-C_2S和β-C_2S,在比表面积相近的条件下,通过XRD、SEM、TG-DSC、游离氧化钙含量和烧失量的测试与分析,对γ-C_2S与β-C_2S在不同温度下的水化活性和常温常压下的碳化反应进行了研究。结果表明:γ-C_2S和β-C_2S的碳化产物主要是方解石和少量的球霰石,γ-C_2S碳化后还有少量的文石生成,并且γ-C_2S的碳化活性略高;在140℃时,γ-C_2S的水化活性较β-C_2S低很多,当温度升高到200℃时,γ-C_2S的水化活性大幅提升,β-C_2S的水化活性也有一定提升,两者的水化活性差距显著缩小。

γ-C2S basically have slow hydration activity,but β-C2S have relatively high hydration activity at room temperature and atmosphere pressure. Both γ-C2S and β-C2S are carbonated under certain humidity and concentration of CO2. γ-C2S and β-C2S with Similar specific surface area are prepared at laboratory. The hydration activity at different temperatures and carbonation reaction at room temperature and atmosphere pressure of γ-C2S and β-C2S are studied by SEM、XRD、TG-DSC,content of free lime and ignition loss. The results show that main carbonation products of γ-C2S and β-C2S are calcite and small amounts of vaterite. Small amounts of aragonite are also produced after γ-C2S ＇s carbonation.Carbonation activity of γ-C2S are slightly higher. The hydration activity of γ-C2S is much more slowly than β-C2S＇s at 140 ℃,the hydration activity of γ-C2S will be greatly improved when the temperature rises to 200 ℃,and the difference of hydration rate became much smaller.