Bond performance of carbon textile reinforced mortar with short fibers for strengthening concrete elements

Abstract

Textile reinforced mortar (TRM) with short fibers exhibits a promising solution for strengthening concrete elements to solve the brittle fracture of the matrix and improve the textile utilization for TRM without short fibers. The strengthening effectiveness of TRM with short fibers is determined by the bond performance of TRM/concrete, where the role of short fibers is non-negligible and requires additional investigation. To this end, the bond properties between carbon TRM with short fibers and concrete substrates were examined in the present study by single shear tests. 45 specimens were tested and analyzed by considering the effects of textile type, number of textile layers, matrix strength, textile orientation, and interface treatment pattern. Experimentally, different volume contents of short fibers were designed to examine the effect of each parameter in different configurations. Textile types were studied to examine the coupling effects between different yarn impregnation and textile mesh geometries. The test results were discussed in the domains of failure modes, load-slip response, and bond parameters. In addition, an explicit analytical model incorporating the contribution of the weft yarn was developed to evaluate the bond-slip model by taking into account the effects of the volume content of the short fibers, the type of short fibers, the bond width, and the surface treatment of the textile.