This paper presents an investigation into the performance of alkali-activated slag (AAS) mortar exposed to elevated temperatures. Sodium silicate, sodium hydroxide and a mix (waterglass) with a modulus (SiO 2/Na 2 0) of 1.5 were used as activators. The specimens were heated in an electric furnace up to 1000 ºC in steps of 200 ºC for a constant period of 2 hours. The weight loss, residual compressive strength, resistance to chloride ion penetration, porosity and capillary sorption were evaluated and the results were compared
