Comparative characterization of the durability behaviour of textile-reinforced concrete (TRC) under tension and bending

Abstract

This paper presents the results of an experimental investigation into the durability behaviour of textile-reinforced concrete (TRC) subjected to both tensile and bending loads to compare its macroscale characterization. Composites are produced as a laminate material using 2 and 6 layers of glass fibre mat as reinforcements. The instantaneous and long-term (durability) properties of composite TRC are identified by tensile and flexural testing with specimens made from the same fresh mortar. The long-term tests are conducted in two ageing environments: natural ageing, which was conducted under the laboratory atmosphere (20°C and 50% RH), and accelerated ageing, which consisted of immersion of the specimens in hot water at 50°C. The durability performance of TRC is evaluated by the reduced macroscale performance and damage mechanisms. The effects of the reinforcement ratio, testing conditions, and thermal conditions on the long-term response of TRC are investigated, and the microstructure of both matrix and fibre is observed and discussed after the tests with observations via scanning electron microscopy (SEM). The addition of layers of glass fibre (reinforcement ratio) increased the strength capacity and the first macro-crack strength of TRC in both tensile and bending tests. The ultimate strength value of the TRC composites obtained from the tensile test is lower than that from the bending test over the same tested days as a result of the different redistribution mechanisms; however, the difference between tensile and flexural stress remains approximately equal with similar deviations. An increase in the tensile and flexural strength capacity over the ageing time is observed before 90days of ageing. However, after 90days, the test results showed a loss of ductility of the accelerated aged specimens.