On the cracking localization in tensile reinforced concrete bars with steel fibers

This paper presents a probabilistic model to explain the phenomenon of crack localization in tensile reinforced concrete (RC) bars with steel fibers. The model quantitatively characterizes a state of crack localization through setting of a criterion for the development of an 'exceptionally wide crack' (EWC). A binomial probability function is proposed, where its maximum value denotes the most expected number of cracks that widen more than the others. Thus, this approach allows prediction of the "localization level" according to the expected number of EWC's under increase load, as oppose to a state ofsimilar widening of the cracks in plain RC. Comparison of the model's prediction with available experimental results shows good agreement and a case study shows that for low reinforcement ratios it is most probable that only one or two cracks will widen while as the conventional reinforcement increases, the widths of the cracks become more uniform.