Abstract:
In this paper, the influence of calcined perlite on the elevated temperature behaviour of alkali-activated slag (AAS) mortars is researched. The diversity parameters of mortars are the levels of calcined perlite (CP) replacement (0, 25, and 50% by volume), the molecular silicate modulus (0.25, 0.50, 0.75, 1.00, and 1.25), and the levels of elevated temperature (400 °C, 600 °C, and 800 °C). The flexural strength (ff), compressive strength (fc), and mass loss of mortars produced according to these diversity parameters are determined. Moreover, X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) analyses are performed on the samples from the mortars exposed to ambient and elevated temperatures. The experimental results prove that the initial ff and fc results of mortars at ambient temperature significantly reduce with the increase of CP content. This decrease in the ff and fc results of mortars is confirmed by the mass losses and microstructure analysis. On the other hand, the experimental results prove that there are significant improvements in the residual strengths of mortars at elevated temperatures with the increase of CP content.