Bond behaviour of prestressed basalt textile reinforced concrete

Abstract

Innovative Textile Reinforced Concrete (TRC) composites, although holding a significant potential, usually have poor performance under serviceability conditions. Addressing this limitation requires applying innovative techniques, such as prestressing, to utilise its potential fully. However, successful design and application of prestressing require a comprehensive understanding of the prestressing effect across scales, including the textile-to-matrix bond behaviour. To address this need, this study investigated the influence of key parameters such as prestressing level, prestressing release time and matrix age on the bond behaviour of basalt textile reinforcement. Test results show a significant influence of prestressing level and release time on textile-matrix bond behaviour. A 1-day prestressing release time resulted in a 25 % increased stiffness with only a 5 % peak load reduction followed by a further 13.7 % increase in the pull-out energy when the prestressing level was 13 %. At 35 % prestress level, 1-day released samples showed a significant reduction of 48.4 % in the peak load and 76 % reduction in the debonding energy. The positive effect of prestressing on the bond behaviour became more evident at prolonged release durations. The 7-day release samples showed a 17.4 % increase in the peak load at both prestress levels. Meanwhile, at 35 % prestress level, 34 % further increase in the debonding energy was observed. The obtained data are then utilised for providing indications on the effect of prestressing on saturated crack spacing of TRC components.