Investigating geometrical size effect on the flexural strength of the ultra high performance fibre reinforced concrete using the cohesive crack model

Geometrical size effect on the flexural strength of the ultra high performance fibre reinforced concrete was investigated by experimental test data and numerical simulation. Comparison of the simulation results to existing experimental test results indicates that the Cohesive Crack Model (CCM) with a bilinear traction–separation curve can provide predictions of both the load–deflection curves and peak load of 100 and 150 mm deep UHPFRC test specimens to =/6% with a little size effect observed on the flexural
strength. However, for the 50 mm deep beams a difference of =/25% was observed between model predictions of the peak load and experiment test data possibly due to a surface layer size effect.