## 1 Introduction  
TRM is an innovative composite material suitable for use as externally bonded strengthening means for strengthening or rehabilitation of existing concrete [1] and masonry [2] structures. In the case of masonry structures, and especially those of a monumental character, TRMs comprise an appealing choice since they: (i) allow for minimal geometry and self-weight change of the strengthened structural members, (ii) are chemically, physically, and mechanically compatible with various substrates, (iii) can be reversible (to a certain extent), (iv) can be applied under low temperatures and/or high humidity conditions, and (v) allow for vapor permeability of the substrate. The quality of bond at both the TRM-to-substrate interface and the textile-to-matrix one is a crucial parameter for the efficient use of this composite material and has received appreciable attention from academia through a number of experimental studies that investigate the effect of individual parameters on bond behavior [3; 4; 5; 6]. Nevertheless, there is only a limited number of studies addressing the effect of elevated or high temperatures (ranges being rather arbitrarily defined in each study) on the bond characteristics of TRM systems. To the authors' knowledge, only two studies exist that focus on the experimental investigation of the residual bond capacity of TRM-to-masonry interfacesafter exposure to elevated/high temperatures. In the study of [PERSON] and [PERSON] [7], a TRM system consisting of a dry AR glass fiber textile embedded in a cementitious matrix was applied on masonry wallettes made of solid clay fair-faced bricks. Single-lap/single-prism tests were conducted after specimens' exposure at 100 \({}^{\circ}\)C, 200 \({}^{\circ}\)C, and 300 \({}^{\circ}\)C for 1 h. It was concluded that the residual shear load that can be undertaken by this type of TRM/masnorry interfaces after exposure at 100 \({}^{\circ}\)C, 200 \({}^{\circ}\)C, and 300 \({}^{\circ}\)C amounts, respectively, to 65%, 60%, and 50% of the respective load reached ambient conditions. In the study of [PERSON] et al. [8], various TRM systems were applied on masonry wallettes: one made of PBO fiber textile and a cement-based matrix while two other were made of dry basalt fiber textiles (of different aerial weight and grid spacing) and a lime-based mortar. Single-lap/single-prism tests were conducted after specimens' exposure at 100 \({}^{\circ}\)C, 150 \({}^{\circ}\)C, and 200 \({}^{\circ}\)C for 3 h. According to the results, the bond response after specimens' heating was affected by the fibers' type and textiles' density. The residual shear bond load decreased by up to 50% and 90% in the case of PBO-TRM and 'heavy' basalt-TRM, respectively, while it remained almost unaffected in the case of the 'light' basalt-TRM ('light' having half the aerial weight of 'heavy'). Furthermore, a numerical model for the simulation of TRMs' bond behavior under different temperatures was proposed by [PERSON] et al. [9]. For the calibration of the model, double-lap/single-prism shear bond tests were conducted (prisms, in this case, standing for single bricks). The TRM systems comprised textiles with either uncoated (dry) or epoxy-impregnated carbon fiber yarns embedded in a cement-based mortar. Specimens were tested under two different regimes: (i) while, at 120 \({}^{\circ}\)C, being conditioned to the same temperature for a duration of 100 min, and (ii) after exposure at 120 \({}^{\circ}\)C for 60 min. It was shown that--when tested under the former heating regime--TRMs with impregnated yarns lost more than half of their bond capacity while the TRMs with dry yarns remained almost unaffected. However, TRMs with impregnated yarns retained almost all of their initial bond capacity when tested under the second heating regime. Lastly, there exist two more studies presenting the results of shear bond tests carried out on concrete specimens furnished with TRM strips both under and after their exposure to elevated/high temperatures.