Diagonal Compression Tests on Unfired and Fired Masonry Wallettes Retrofitted with Textile-Reinforced Alkali-Activated Mortar

This paper discusses the integration of an alkali-activated mortar (AAM), based on industrial waste, into a novel composite material fit for structural upgrading purposes and rendered with high temperature endurance and a low CO₂ footprint. The AAM combined with carbon fiber textiles form a new generation of sustainable inorganic matrix composites—that of textile-reinforced alkali-activated mortars (TRAAM). A test program was designed to assess the effectiveness of carbon TRAAM overlays in increasing the shear capacity of masonry wall specimens comprising solid clay bricks bonded with lime-based mortar and furnished with TRAAM jackets on both sides. The initial and the residual capacity of the reinforced walls were evaluated, the latter by performing diagonal compression tests after exposure to 300 °C and 550 °C. It was shown that TRAAM jacketing can increase the shear capacity of unfired masonry walls by 260% and 335% when a single or a double layer of textile is used, respectively. Rapid heating to temperatures up to 550 °C, one-hour-long steady-state heating, and natural cooling bore no visible thermal cracks on the specimens and had little effect on their residual capacity. Based on these results, the prospect of using TRAAM for retrofitting applications for fire-resilient structures seems very auspicious.