A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Comparing pozzolanic activity from thermal-activated water-washed and coal-series kaolin in Portland cement mortar
https://orcid.org/0000-0003-3298-2339
Highlights The crystallinity of coal-series and water-washed kaolin are investigated. The coal-series kaolin with poor crystallinity presents a lower pozzolanic activity. The increase of amount of AlV and AlVI results in a higher pozzolanic activity.
Abstract In this paper, we investigated the pozzolanic activity of thermal-activated coal-series kaolin and two types of water-washed kaolin, which were calcined at temperatures ranging from 600 to 700 °C for 3 h. Chapelle test and strength activity index were used to evaluate the pozzolanic activity of thermal-treated kaolin. Results indicated that thermal-activated water-washed kaolin presented a higher pozzolanic activity when calcined at same temperature, which is due to its well-defined morphology, relatively high specific surface area, and high amounts of active aluminum. The incorporation of 10 wt% of calcined kaolin significantly increased the amount of hydrate water and promoted strength development at 7 and 28 days. Moreover, the crystallinity of kaolinite showed obvious impacts on the dehydroxylation temperature and aluminum structure. The optimum dehydroxylation temperature is mainly dependent on the crystallinity of the kaolinite; in addition, the aluminium structure is closely related to the kaolinite crystallinity. Well-crystallized kaolin showed higher pozzolanic activity than poorly crystallized kaolin at the same calcination condition.
Comparing pozzolanic activity from thermal-activated water-washed and coal-series kaolin in Portland cement mortar
https://orcid.org/0000-0003-3298-2339
Highlights The crystallinity of coal-series and water-washed kaolin are investigated. The coal-series kaolin with poor crystallinity presents a lower pozzolanic activity. The increase of amount of AlV and AlVI results in a higher pozzolanic activity.
Abstract In this paper, we investigated the pozzolanic activity of thermal-activated coal-series kaolin and two types of water-washed kaolin, which were calcined at temperatures ranging from 600 to 700 °C for 3 h. Chapelle test and strength activity index were used to evaluate the pozzolanic activity of thermal-treated kaolin. Results indicated that thermal-activated water-washed kaolin presented a higher pozzolanic activity when calcined at same temperature, which is due to its well-defined morphology, relatively high specific surface area, and high amounts of active aluminum. The incorporation of 10 wt% of calcined kaolin significantly increased the amount of hydrate water and promoted strength development at 7 and 28 days. Moreover, the crystallinity of kaolinite showed obvious impacts on the dehydroxylation temperature and aluminum structure. The optimum dehydroxylation temperature is mainly dependent on the crystallinity of the kaolinite; in addition, the aluminium structure is closely related to the kaolinite crystallinity. Well-crystallized kaolin showed higher pozzolanic activity than poorly crystallized kaolin at the same calcination condition.
Comparing pozzolanic activity from thermal-activated water-washed and coal-series kaolin in Portland cement mortar
https://orcid.org/0000-0003-3298-2339
Highlights The crystallinity of coal-series and water-washed kaolin are investigated. The coal-series kaolin with poor crystallinity presents a lower pozzolanic activity. The increase of amount of AlV and AlVI results in a higher pozzolanic activity.
Abstract In this paper, we investigated the pozzolanic activity of thermal-activated coal-series kaolin and two types of water-washed kaolin, which were calcined at temperatures ranging from 600 to 700 °C for 3 h. Chapelle test and strength activity index were used to evaluate the pozzolanic activity of thermal-treated kaolin. Results indicated that thermal-activated water-washed kaolin presented a higher pozzolanic activity when calcined at same temperature, which is due to its well-defined morphology, relatively high specific surface area, and high amounts of active aluminum. The incorporation of 10 wt% of calcined kaolin significantly increased the amount of hydrate water and promoted strength development at 7 and 28 days. Moreover, the crystallinity of kaolinite showed obvious impacts on the dehydroxylation temperature and aluminum structure. The optimum dehydroxylation temperature is mainly dependent on the crystallinity of the kaolinite; in addition, the aluminium structure is closely related to the kaolinite crystallinity. Well-crystallized kaolin showed higher pozzolanic activity than poorly crystallized kaolin at the same calcination condition.
Comparing pozzolanic activity from thermal-activated water-washed and coal-series kaolin in Portland cement mortar
Sun, Tao (author) / Ge, Keyu (author) / Wang, Guiming (author) / Geng, Haining (author) / Shui, Zhonghe (author) / Cheng, Shukai (author) / Chen, Meng (author)
2019-09-26
Article (Journal)
Electronic Resource
English
Assessment of pozzolanic activity of calcined coal-series kaolin
| Elsevier | 2017
Thermally activated dolomite as pozzolanic addition to Portland cement
| Online Contents | 2016
Microstructure of Portland cement mortar amended by burnt kaolin sand
| Springer Verlag | 2010
Thermal stability and pozzolanic activity of calcined kaolin
| Online Contents | 1994