Experimental behavior of injected geopolymer grout using styrene-butadiene latex for the repair and strengthening of masonry walls

Unreinforced masonry buildings in the historic centers of the world have often been overlooked for centuries without any protection. These buildings demonstrate low resistance under external effects, especially against earthquakes. Earthquakes cause serious damage to the buildings and even the collapse of structures as a result of seismic stimulation from the impact of pounding with structural impacts. For this reason, it is of great importance to repair and strengthen damaged masonry structures. This study investigated the testing of masonry wall specimens produced from different kinds of masonry units with various types of mortar. Then, geopolymer grouts with high mechanical properties were produced by using alkali activation and industrial products. The experimental performance of strengthened masonry wall samples was determined using the optimum geopolymer grout in vertical compression tests. The behavior, failure mode, and crack pattern of the masonry wall samples were determined under loading systems. Experimental results demonstrate that the use of additive styrene-butadiene (SB) latex geopolymer grouts on damaged walls increased the load-carrying capacity and ductility significantly compared to the corresponding values of samples before initial failure. All of the strengthened walls failed through the de-bonding failure mode, and no visible damage was observed on the samples. Consequently, geopolymer grouts displayed many advantages over conventional repair materials due to their high viscosity, compressive strength, eco-friendliness, and excellent resistance.