论文部分内容阅读
研究了石灰石粉对碱激发胶凝材料强度的影响,并分析了掺石灰石粉前后其水化产物、微观结构的变化。结果表明:石灰石粉对强度有显著影响,但对早期(3 d)和后期(28 d)强度的影响有很大区别;当石灰石粉掺量不超过15%时,3 d强度并没有明显下降,但继续增加至25%会导致微米级大孔及石灰石粉/凝胶界面弱化区增多,进而引起强度显著下降;与3 d强度变化规律不同,28 d强度随着石灰石粉掺量的增加而不断降低;掺石灰石粉并不会导致新物相出现,且掺入的石灰石粉以几乎等量的方解石形式存在;石灰石粉掺量不高于15%的3 d试样表现出更低的孔隙率,而经历28 d的长时间碱激发反应后,掺与不掺石灰石粉的试样具有相当的孔隙率。石灰石粉在该胶凝材料中主要起物理作用(填充效应),其化学作用有限。
The effect of limestone powder on the strength of alkali-activated cementitious materials was studied, and the changes of hydration products and microstructure before and after limestone powder addition were analyzed. The results showed that: the limestone powder had a significant effect on the strength, but the effect on the strength at the early (3 d) and the late (28 d) was quite different. When the limestone powder content did not exceed 15%, the 3 d strength did not significantly decrease , But continued to increase to 25%, which led to the increase of micron-sized macropores and limestone powder / gel interfacial weakening zone, which in turn led to a significant decrease in strength. Different from the 3 d intensity variation, with the increase of limestone powder content, The limestone powder did not appear new phase, and the mixed limestone powder existed in the form of almost equal amount of calcite. The 3 d limestone powder with the limestone powder content less than 15% showed lower porosity Rate, and experienced 28 days after a long alkali activation reaction, mixed with the sample without limestone powder has a considerable porosity. Limestone powder mainly plays a physical role (filling effect) in the cementitious material, and its chemical effect is limited.