Effectiveness of TRC jackets for the strengthening of concrete columns after elevated temperatures: Experimental and analytical investigation

Abstract

Textile reinforced concrete (TRC) materials with high strength and excellent heat resistance might considerably enhance the performance of structures under thermal conditions. This study examined thirty concrete columns, each reinforced with varying TRC configurations, and subjected them to different high-temperature scenarios. Axial compression experiments were subsequently carried out to assess the impact of TRC on concrete's performance at elevated temperatures. Key variables in these tests included different textile layers (0–4 layers), and a temperature range extending from room temperature to 800 °C. The application of TRC was found to facilitate more gradual failure progress during compression tests. In contrast to the unconfined specimens, whose stress-strain curves exhibited a parabolic pattern, those reinforced with TRC displayed a hardening segment at temperatures up to 400 °C. The presence of TRC jackets significantly improved the compressive strength, the ultimate axial strain, and the energy dissipation, both at room temperature and after high-temperature treatments. Furthermore, this paper proposed an innovative model for estimating the residual strength of TRC-confined cylinders after being exposed to various temperatures. This model accounted for the impact of high temperature on the residual bearing capacity of unconfined cylinders, the modulus of elasticity for fibers, and the confinement effectiveness coefficient.