Scale effects in the post-cracking behaviour of fibre-reinforced concrete beams

Abstract The scale effects on the global structural response of fibre-reinforced concrete (FRC) beams subjected to bending are discussed in framework Fracture Mechanics by means Updated Bridged Crack Model (UBCM). This model predicts different post-cracking regimes depending two dimensionless numbers: reinforcement brittleness number , N P which is related fibre volume fraction, V f ; and pull-out w embedment length, c . Both these numbers depend beam depth, h which, keeping other variables be constant, drives a ductile-to-brittle transition regime composite. critical value number, PC allows for prediction minimum (critical) specimen size, min analogously f,min required achieve stable response. Numerical simulations compared experimental results reported scientific literature, FRC specimens, characterized same fraction but sizes, tested bending.