Experimental evaluation of size effect on the fracture response of glass textile reinforced concrete

Abstract

Textile Reinforced Concrete (TRC) is a strain-hardening cementitious composite that integrates bi-directional fabric reinforcement within a fine-grained concrete matrix, enabling the development of thin, lightweight structural and non-structural systems. This study investigates the influence of specimen thickness on the uniaxial tensile behaviour of TRC panels, using panels of varying thicknesses—10, 20, and 40 mm, reinforced with coated E-glass textiles. Two sets of TRC panels were analysed: (i) panels with a constant reinforcement ratio and (ii) panels with the same number of textile layers. The displacement and cracking behaviour including crack patterns, spacing, and openings at different strain levels, were assessed using axial extensometers and 2D Digital Image Correlation. The findings reveal a reduction in the first-crack stress with increasing panel thickness, which is consistent with the Weibull model. Additionally, a decrease in ultimate stress and textile efficiency is observed in larger panels though the reinforcement ratio is constant. Such reduction is attributed to a shift in failure mechanisms, from textile fracture to extensive debonding in some of the specimens, as the number of reinforcement layers increases, possibly due to the increase in defects with larger interface (bond) area. Thinner panels exhibit higher crack density, reduced crack spacing, and finer crack widths, at comparable strain levels. For the same number of layers, thicker panels experience wider cracks at a given nominal strain; longer yarn lengths that bridge the cracks are mobilised leading to a Weibull-type size effect, which reduces the load-carrying capacity of the textiles.