Pozzolanic activity of burned coal gangue and its effects on structure of cement mortar
- 122 Downloads
The pozzolanic activity of coal gangue burned at different burning temperatures was investigated. The burned coal gangue was mixed with portland cement in different proportions (20%–60%). The pozzolanic activity of coal gangue burned and the hydration, products were examined, the compressive strengths of the pastes of the mixtures were tested, and the mechanism of the reaction was discussed. The experimental results show that the coal gangue burned at 750 °C has the optimum pozzolanic activity, and the burned coal gangue with SiO2 and Al2O3 is in an active form. When the coal gangue burned at 750 °C is mixed into portland cement, the content of calcium hydroxide in paste is significantly reduced, while the contents of hydrated calcium silicate and hydrated calcium aluminate are increased accordingly, hence resulting in the improvement of the microstructure of mortar. The compressive strength of cement paste decreases with increasing the content of burned coal gangue. The decease in strength is small in the range of 20%–30% coal gangue substitution and significant in 30%–60% substitution.
Key wordscoal gangue burn pozzolanic activity cement mortar strength
Unable to display preview. Download preview PDF.
- Cai Jingqang. A New Approach to High-effective Use of Coal Gangue[J].J. Rare and Hard Metal., 2000, (6): 37Google Scholar
- Clement Greco and Guido Picciotti. Pozzolan Production[J].J. World Cement, 2001, 32(10): 39–43Google Scholar
- Ding Zhu, Zhang Decheng, Wang Xiangdong. Research and Application of Pozzolanic Activity of Metakaolin[J].J. Bulletin of the Chinese Ceramic Society, 1997, (4): 57–62Google Scholar
- Gao Qiongying, Zhang Zhiqiang. Study on the Structure Change in the Calcination Process of Kaolinite and Its Pozzolanic Activity [J].J. Journal of the Chinese Ceramic Society, 1998, 17(6): 541–548Google Scholar