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The role of alumina on performance of alkali-activated slag paste exposed to 50 C

Version 2 2024-06-04, 05:38
Version 1 2015-09-30, 16:18
journal contribution
posted on 2024-06-04, 05:38 authored by N Jambunathan, JG Sanjayan, Z Pan, G Li, Y Liu, AH Korayem, WH Duan, Frank CollinsFrank Collins
The strength and microstructural evolution of two alkali-activated slags, with distinct alumina content, exposed to 50 °C have been investigated. These two slags are ground-granulated blast furnace slag (containing 13% (wt.) alumina) and phosphorous slag (containing 3% (wt.) alumina). They were hydrated in the presence of a combination of sodium hydroxide and sodium silicate solution at different ratios. The microstructure of the resultant slag pastes was assessed by X-ray diffraction, differential thermogravimetric analysis, and scanning electron microscopy. The results obtained from these techniques reveal the presence of hexagonal hydrates: CAH10 and C4AH13 in all alkali-activated ground-granulated blast-furnace slag pastes (AAGBS). These hydrates are not observed in pastes formed by alkali-activated ground phosphorous slag (AAGPS). Upon exposure to 50 °C, the aforementioned hydration products of AAGBS pastes convert to C3AH6, leading to a rapid deterioration in the strength of the paste. In contrast, no strength loss was detected in AAGPS pastes following exposure to 50 °C.

History

Journal

Cement and concrete research

Volume

54

Pagination

143-150

Location

Amsterdam, The Netherlands

ISSN

0008-8846

Language

eng

Notes

Cited By :2 Export Date: 15 September 2015

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2013 Elsevier

Publisher

Elsevier