Comprehensive studies of the influence of superficial strengthening with the FRCM system on the load‐bearing capacity and deformability of AAC walls

This article presents the results of tests on walls made of AAC (autoclaved aerated concrete) strengthened with the FRCM system. The effect of the applied strengthening was determined based on the results of tests on masonry models subjected to compression, diagonal compression and shear. Models of walls without strengthening, strengthened on one and two sides were tested. The research models were built of masonry elements made of autoclaved aerated concrete (AAC) SOLBET OPTIMAL 4/600. The walls were erected on a system thin‐layer mortar, class M5, without filling the head joints. PBO fiber meshes embedded in a mineral matrix were used as superficial reinforcement. The walls were strengthened by applying the PBO‐MX GOLD MASONRY system mortar to the side surfaces of the models and the PBO‐MESH GOLD 22/22 mesh was embedded in it, and then the top layer of the PBO‐MX GOLD MASONRY system mortar was applied. The compressive strength test was performed on 18 models in accordance with the requirements of the PN‐EN 1052‐1: 2000 standard. In the case of compression, additional tests were performed on models weakened by a cut imitating cracking. The diagonal compression test was performed on 18 models in accordance with the requirements of ASTM E519‐81 standard. The shear load test was performed on 27 models in accordance with the requirements of the PN‐EN 1052–3: 2004 standard. A clear increase in load capacity in each type of test was noted in models strengthened on two sides. In models strengthened on one side, the positive effect of strengthening was observed only by increasing the deformability of the wall. Regardless of the test type, the use of surface reinforcement allowed for smoother behavior of the test models after the loss of load capacity in relation to models without strengthening.