An investigation on blast-furnace stag as fine aggregate in alkali-activated slag mortars subjected to elevated temperatures
2015; Elsevier BV; Volume: 112; Linguagem: Inglês
10.1016/j.jclepro.2015.07.127
ISSN1879-1786
AutoresAlaa M. Rashad, Dina M. Sadek, Hassan A. Hassan,
Tópico(s)Fire effects on concrete materials
ResumoIn this study, the possibility of using granulated blast-furnace slag (GBFS) as partial or full natural silica sand replacement in alkali-activated slag (AAS) mortar was investigated. The ratio of binder to fine aggregate was 1:2. Natural sand was replaced with GBFS at levels of 0%, 25%, 50%, 75% and 100%, by weight. Compressive strength at ages of 7 and 28 d was measured. The behaviour of the investigated mortar mixtures after exposure to 200, 400, 600 and 800 °C for 2 h was evaluated quantitatively by measuring the residual compressive strength and qualitatively by visual inspection. The various decomposition phases formed and the morphology of formed hydrates were identified by using X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results indicated that the compressive strength of the mortar specimens before and after firing increased with increasing GBFS sand content.
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