FRCM–Masonry Joints at High Temperature: Residual Bond Capacity

The paper describes the results of an experimental investigation into the bond behavior of fabric-reinforced cementitious matrix (FRCM)–masonry joints after exposure to high temperature. Single-lap direct shear tests (DS) were conducted on three different thermally conditioned FRCM composites applied to a clay brick masonry substrate. The FRCM studied comprised one layer of basalt, steel, and PBO (short for polypara-phenylene-benzo-bisthiazole) textile embedded within two inorganic matrices (cement based for the PBO FRCM composite and lime based for the basalt and steel FRCM composites). The joints were tested under residual conditions after exposure inside a thermal chamber for three hours at the target temperatures of 20°C, 100°C, 300°C, and 500°C. The thermal performances of the mortar matrices used in the FRCM systems were analyzed by X-ray diffractometry, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results show a peculiar bond behavior and failure mode for each composite.