The bond property between concrete confined with textile-reinforced concrete and a steel bar

Abstract

In this paper, based on pull-out test results, the influence of the number of chloride wetting–drying cycles, concrete strength, cover thickness, steel bar diameter and number of textile layers used in the textile-reinforced concrete (TRC) confinement on the bond property between concrete and a steel bar is analysed. Furthermore, a bond strength model is developed and the confinement effect of TRC and fibre-reinforced polymer is compared. The study results show that the ultimate bond strength decreased slightly as the number of chloride wetting–drying cycles increased, because only a slight corrosion of the steel bars was observed in this test. The influence of the concrete strength on the ultimate bond strength of the unconfined specimens was significantly higher than that of the TRC-confined specimens, and the improvement effect of TRC confinement was more pronounced for the low-strength concrete. Compared with the concrete strength, the cover thickness and steel bar diameter had less influence on the ultimate bond strength. With an increase in the number of textile layers, the ultimate bond strength improved significantly, and TRC confinement showed a better ability to limit the crack development in the confined specimens in which more than one layer of textile was used.