Crack behaviour and flexural response of steel and chopped glass fibre-reinforced concrete: Experimental and analytical study

Abstract

Steel and glass fibres are commonly used to reinforce concrete for improved toughness, durability, and peak post-cracking response. Comprehension of the flexural and cracking behaviour of fibre-reinforced concrete (FRC) is important since fibres increase moment resistance and stiffness. This study investigated the flexural and cracking behaviour of FRC prisms through experimental and analytical methods. Forty prisms (150 × 150 × 500 mm) were tested in flexure and 50 cylinders (100 × 200 mm) were loaded under splitting tensile testing to assess the effect of adding steel and/or glass fibres with three dosages (0.5, 1.0, and 1.5% by volume fraction) on flexural and splitting tensile response. Digital Image Correlation investigated crack formation and propagation in the flexure tests. An Inverse Analysis (IA) was used to generate the tensile stress-strain response for FRC. Proposed tensile stress-strain model for FRC considers the influence of steel and glass fibres and is presented in design-oriented expressions for equivalent stress block parameters. Results showed fibres significantly increase flexural strength, splitting tensile strength, residual stresses, and toughness. IA results were used to develop the tensile model of FRC, and the simplified proposed model adequately represents the flexural response of FRC.