Compressive behaviour of steel fibre reinforced concrete

R. D. Neves, Concrete Division, LNEC, Portugal
J. C. O. Fernandes de Almeida, Civil Engineering Dept., Instituto Superior Tecnico, Portugal

An experimental study to investigate the influence of matrix strength, fibre content and diameter on the compressive behaviour of steel fibre reinforced concrete is presented. Two types of matrix and fibres were tested. Concrete compressive strengths of 35 and 60 MPa, 0.38 and 0.55 mm fibre diameter, and 30 mm fibre length, were considered. The volume of fibre in the concrete was varied up to 1.5%. Test results indicated that the addition of fibres to concrete enhances its toughness and strain at peak stress, but can slightly reduce the Young's modulus. Simple expressions are proposed to estimate the Young's modulus and the strain at peak stress, from the compressive strength results, knowing fibre volume, length and diameter. An analytical model to predict the stress-strain relationship for steel fibre concrete in compression is also proposed. The model results are compared with experimental stress-strain curves.