The microstructure of 4-year-old hardened cement-fly ash paste
The microstructure of 4-year-old hardened cement-fly ash paste
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DOI：
10.1016/j.conbuildmat.2011.08.088
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发表时间：
2012-04
影响因子：
7.4
通讯作者：
Qiang Wang;Jingjing Feng;P. Yan
中科院分区：
文献类型：
--
作者：
Qiang Wang;Jingjing Feng;P. Yan
本文研究了掺量为50%的粉煤灰水泥-粉煤灰复合材料4年硬化浆体的微观结构。水泥水化产生的Ca（OH）2在4a内被粉煤灰的火山灰反应消耗了65.44%，水泥-粉煤灰硬化浆体4a时Ca（OH）2含量仅为3.15%。大多数小的飞灰颗粒反应剧烈，但许多大的飞灰颗粒几乎保持未反应。4a后粉煤灰残留率为72.7%，说明粉煤灰在浆体硬化过程中起了物理作用。与水泥浆体相比，粉煤灰在90天至4a的时间内，由于火山灰反应的影响，水泥-粉煤灰浆体的孔结构得到了较为显著的改善。4年硬化水泥-粉煤灰浆体中凝胶的平均Ca/Si、Al/Si和Ca/（Si+Al）原子比分别为1.52、0.33和1.15，表明凝胶具有较低的Ca/Si原子比，且比波特兰水泥浆体中的Al含量更高。
In this study, the microstructure of 4-year-old hardened cement-fly ash paste containing 50% fly ash has been investigated. 65.44% of Ca(OH)2produced by cement hydration is consumed by the pozzolanic reaction of fly ash in 4years and the Ca(OH)2content of the hardened cement-fly ash paste is only 3.15% at the age of 4years. Most of the small fly ash particles react heavily but many large fly ash particles remain almost unreacted. 72.7% of fly ash remains after 4years, which indicates that most of the fly ash takes physical effect during the hardening process of paste. Compared with cement paste, there is a relative more significant improvement of the pore structure of cement-fly ash paste due to the pozzolanic reaction of fly ash from 90days to 4years. The mean Ca/Si, Al/Si, and Ca/(Si+Al) atom ratios of the gel in the 4-year-old hardened cement-fly ash paste are 1.52, 0.33 and 1.15 respectively, which indicate that the gel has a lower Ca/Si atom ratio and is richer in Al content than that of Portland cement paste.