Experimental and analytical study of the thermo-mechanical behaviour of textile-reinforced concrete (TRC) at elevated temperatures: Role of discontinuous short glass fibres

Abstract

During the last few decades, textile-reinforced concrete materials are being increasingly used to repair and/or reinforce civil engineering structures, owing to their many advantages (nontoxicity, availability of raw materials, recyclability, simplicity of implementation, etc.). However, the elevated temperature resistance of these materials has not been studied to a great extent. The present work was aimed at studying the tensile behaviour of two types of such composite materials (3GRI and 3GRI.SF), under combined thermal and mechanical loading. 3GRI was composed of a cement matrix, and alkali-resistant (AR) grid glass textile. 3GRI.SF was also composed of the same matrix and textile reinforcement (as 3GRI), but with discontinuous, short AR glass fibres. Using an original experimental approach, the thermo-mechanical behaviour of these two types of composite materials could be identified at various temperatures (from 20 °C to 600 °C), and the role and efficiency of the addition of discontinuous short fibres were investigated. The experimental study was followed by analytical modelling, which helped calibrate other existing analytical models (Gibson and Bisby). Based on these models, and on the experimental results, the parameters of suitable models for the textile-reinforced concrete composites (3GRI and 3GRI.SF) were identified and commented on. This paper shows that the addition of short glass fibres had a positive effect on the tensile strength, stiffness and resistance to crack. The calibrated analytical models allowed predicting the thermomechanical proprieties of glass TRC with a minimum of experimental tests. The calibrated analytical models can be applied for the prediction of the thermomechanical proprieties of similar TRC.