TY - JOUR
T1 - The role of alumina on performance of alkali-activated slag paste exposed to 50 °C
AU - Jambunathan, N.
AU - Sanjayan, J. G.
AU - Pan, Z.
AU - Li, G.
AU - Liu, Y.
AU - Korayem, A. H.
AU - Duan, W. H.
AU - Collins, F.
PY - 2013
Y1 - 2013
N2 - 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 C4AH 13 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 C 3AH6, 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.
AB - 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 C4AH 13 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 C 3AH6, 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.
UR - http://handle.uws.edu.au:8081/1959.7/548700
U2 - 10.1016/j.cemconres.2013.09.009
DO - 10.1016/j.cemconres.2013.09.009
M3 - Article
SN - 0008-8846
VL - 54
SP - 143
EP - 150
JO - Cement and Concrete Research
JF - Cement and Concrete Research
ER -