Influence of slag chemistry on the hydration of alkali-activated blast-furnace slag - Part II: Effect of Al{sub 2}O{sub 3}

Journal Article · Sun Jan 15 04:00:00 EST 2012 · Cement and Concrete Research

DOI:https://doi.org/10.1016/j.cemconres.2011.08.005· OSTI ID:21596949

Ben Haha, M; Lothenbach, B; Le Saout, G; Winnefeld, F

The hydration and microstructural evolution of three alkali activated slags (AAS) with Al{sub 2}O{sub 3} contents between 7 and 17% wt.% have been investigated. The slags were hydrated in the presence of two different alkaline activators, NaOH and Na{sub 2}SiO{sub 3}{center_dot}5H{sub 2}O. The formation of C(-A)-S-H and hydrotalcite was observed in all samples by X-ray diffraction, thermal analysis and scanning electron microscopy. Higher Al{sub 2}O{sub 3} content of the slag decreased the Mg/Al ratio of hydrotalcite, increased the Al incorporation in the C(-A)-S-H and led to the formation of straetlingite. Increasing Al{sub 2}O{sub 3} content of the slag slowed down the early hydration and a lower compressive strength during the first days was observed. At 28 days and longer, no significant effects of slag Al{sub 2}O{sub 3} content on the degree of hydration, the volume of the hydrates, the coarse porosity or on the compressive strengths were observed.

• OSTI ID: 21596949
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Journal Issue: 1 Vol. 42; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALKALI METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
COHERENT SCATTERING
COMPRESSION STRENGTH
DIFFRACTION
ELECTRON MICROSCOPY
HYDRATES
HYDRATION
HYDROGEN COMPOUNDS
HYDROXIDES
MECHANICAL PROPERTIES
MICROSCOPY
MICROSTRUCTURE
OXIDES
OXYGEN COMPOUNDS
POROSITY
SCANNING ELECTRON MICROSCOPY
SCATTERING
SILICATES
SILICON COMPOUNDS
SLAGS
SODIUM COMPOUNDS
SODIUM HYDROXIDES
SODIUM SILICATES
SOLVATION
THERMAL ANALYSIS
X-RAY DIFFRACTION