Bonding of TRM and Salt Erosion–Degraded Masonry: Experimental Characterization and Analysis

Abstract

This study investigated the interfacial bonding between textile-reinforced mortar (TRM) and erosion-deteriorated masonry using single shear testing and digital image correlation. Various factors, including the number of dry-wet cycles, concentration of salt solution, and type of matrix, were explored for their influence on the interfacial bonding. Fine-grained concrete, mortar, and engineered cementitious composites (ECCs) served as TRM matrixes. The findings revealed that the failure mode of the TRM-reinforced erosion-deteriorated masonry specimens was primarily fabric slippage within the matrix. During the loading process, when the tensile stress of the fabric was greater than its tensile strength, the fabric broke. The pores inside the masonry and the matrix did not hinder the transport of salt and water. In addition, salt crystallization reached the surface of the matrix through either capillary action or diffusion only when a sufficient degree of salt crystallization was induced by at least 12 dry-wet cycles in the masonry. This occurred after moisture was introduced into either the matrix material or laboratory air. When specimens with ECC as the matrix were subjected to 6 and 12 dry-wet cycles, their ultimate loads increased by 43% and 26%, respectively, and their slip value decreased by 15% and 39%, respectively, compared with those of uneroded specimens. This suggests that the utilization of the ECC matrix enhanced the interfacial bonding of the specimens. The energy release rate was associated with the textile and matrix material, but only the effect of the latter on the energy release rate was investigated in this study. Except for the specimens with ECC as the matrix, the eroded specimens exhibited an energy release rate lower than that of the uneroded specimens.