Experimental investigations on glass fibre reinforced composites with gypsum-earth matrix to strengthen the earth walls of the Noh-Gonbad Mosque in Balkh, Afghanistan

The Noh Gonbad mosque is an almost unknown masterpiece dated back to the 8th century, located near Balkh, North Afghanistan. The archaeological remains show different buildings techniques such as rammed earth (for portions perimeter walls), adobe masonry (for walls, niches and abutment of the arcades) and bricks with earthen or gypsum mortar (for domes, arch and columns). The state of ruin required targeted intervention strategies for perimeter walls. The presence of collapse debris, and the possibility of their removal, would though increase, for the masonry portions, the vulnerability against overturning connected to the seismic hazard at the site. The reported experimental campaign focus on the identification of a fibre-reinforced composite system aimed at jacketing perimeter walls. Tests addresse different matrix compositions compatible with the substrate, i.e. based on earth and gypsum. Results enable to highlight the effect that the composition has on the mechanical response and suggest the most compatible solution.