Bond strength evaluation between textiles reinforced mortar with carbon nanotubes and concrete substrate
Abstract The influence of using carbon nanotubes to improve bond strength between textiles reinforced mortar and concrete was investigated. Forty-two specimens were tested using double-shear test to evaluate the effect of various parameters such as CNTs addition, type of textile material, bond length and width, and number of TRM layers on the bond behavior. Two types of textile: carbon and basalt fibers were used. Various bond length and width including 50 mm, 100 mm, and 150 mm were considered. Three different percentages of CNTs; 0.05%, 0.1%, and 0.2% by weight of cement, were used. The effect of CNTs addition on the mechanical strength of cement mortar and pull-off strength of TRM were also investigated. Test results showed that adding small amount of CNTs enhanced the tensile and flexural strength of cement mortar, the pull-off strength of the TRM, and the ultimate bond load between the TRM and concrete substrate. The ultimate bond load was highly dependent on the amount of added CNTs, type of textile material, geometry of the bonded area, and number of TRM layers. The SEM images showed the role of the CNTs to enhance the adhesion at the fiber-matrix interface.