Influence of prestressing the textile on the tensile behaviour of textile reinforced concrete

In textile reinforced concrete (TRC), the yarns of the textiles are inherently wavy due to the manufacturing process. In most structural applications, this leads to delayed activation of textiles during loading and affects the composite performance negatively. In this context, the paper reports on the significance of mechanically prestressing or stretching the textiles before casting the TRC towards enhancing its load-carrying ability, which has been assessed by comparing the responses of specimens with textiles placed by manual and mechanical stretching. Studies were carried out to determine the uniaxial tensile behaviour of TRC with two types of alkali-resistant glass textiles, woven and bonded and their combinations. TRC with mechanically-stretched woven textile exhibits better performance compared to that of the manually stretched textile, in terms of load-carrying ability though the elongation at failure could be compromised for specimens with bonded textiles. Mechanically stretched textile lead to pronounced strain hardening behaviour, enhancement in the stress at first cracking and stress at peak, which also increase as the number of layers increases. The failure of TRC with manually stretched textile occurs with the pullout of the textile from the matrix contrasting with the rupture of textile when mechanically stretched. X-ray tomography images of the internal structure of TRC further revealed that there is less frictional bond loss and debonding of textile from the matrix for mechanically stretched textile.