Brick masonry reinforcement with methyl methacrylate injection

Introduction. Structural reinforcement of brick and stone masonry by grouting materials under pressure is an efficient approach to restoring the masonry integrity, and, in some cases, improving its bearing capacity. This paper presents the results of research studies into the strength of a masonry structure reinforced by methyl methacrylate injection. This research is part of a larger project, which was launched in 2004 and continues to date. Due to the high penetrating ability of methyl methacrylate, reinforcement of masonry structures with small crack opening seems highly promising. Aim. Evaluation of the effectiveness of methyl methacrylate injection for masonry reinforcement. Materials and methods. The experimental studies were carried out in two stages. At the first stage, masonry specimens manufactured in the form of columns were subjected to compression tests. At the second stage, methyl methacrylate was injected under pressure into the specimens with formed cracks. The as-reinforced specimens were tested again in order to evaluate their strength increase factor. Results. The distribution of methyl methacrylate throughout masonry when injected under pressure, as well as through individual brick and mortar specimens without pressure, was studied. It is shown that the technology of masonry reinforcement by methyl methacrylate differs significantly from that of concrete consolidaton, where higher pressures contribute to its more even distribution over the concrete body. Conclusions. Injection of methyl methacrylate into masonry with multiple load cracks can increase its loadbearing capacity by at least 1.2 times. The results of research were used in the development of normative documents on reinforcement of masonry structures.