Flexural strengthening of RC beams with textile-reinforced mortar composites focusing on the influence of the mortar type

Abstract

This paper presents an experimental study on the flexural strengthening of reinforced concrete (RC) beams with externally bonded layers of textile-reinforced mortar (TRM), as a means of improving their flexural response. The main aim of this study was to investigate the effect of the mortar type in the performance of TRM strengthening system, while varying the type of the textile and the number of the textile layers. In total, nine medium-scale RC beams were manufactured and tested as simply supported under 4-point bending. One beam was tested as-built without strengthening and served as control specimen. The rest of the beams were first strengthened with different configurations and then were subjected in monotonic bending. The parameters under investigation included: a) the mortar type (two different mortars were used, M1 and M2), b) the number of strengthening layers (three versus six), and c) the type of the textile (basalt-fibre with small mesh-size versus glass-fibre textile with large mesh-size). The main difference between mortars M1 and M2, was the use of synthetic polymers as additives in mortar M1. It was overall concluded that there is a strong influence of the mortar type on the flexural capacity increase, on the flexural stiffness response after yielding, as well as on the failure modes. Combined effects between the different type of mortars and the rest of the investigated parameters were also revealed. © 2021 Elsevier Ltd