Using textile reinforced mortar modified with carbon nano tubes to improve flexural performance of RC beams

Textile reinforced mortar (TRM) represents one of the alternatives to substitute the fiber reinforced polymer (FRP) composites to strengthening reinforced concrete structures. This paper investigates the influence of using carbon nano tubes (CNTs) to enhance the flexural performance of reinforced concrete (RC) beams strengthen with TRM. Twenty-six RC beams were prepared, strengthened using either TRM or nano-modified TRM, and tested under four-point bending. The investigated parameters include the modification of cement mortar with CNTs, number of TRM layers, type of cementitious binder materials, and type of textile materials. Experimental results showed that the CNTs addition improved the compressive and flexural strengths of the cementitious binder materials used in this study. Using cementitious binder with CNTs caused marginal enhancement in the flexural capacity but significant enhancement in the initial stiffness of beams strengthen with single layer of TRM. The enhancement in the flexural capacity of the strengthen beams due to CNTs addition affected by the type of cement matrix, whereas the enhancement in the stiffness of the strengthen beams was affected by the type of the textile material. Using multi-layer TRM with CNTs caused debonding of the TRM layers.