Influence of rebar diameter in concrete cracking studied using a discrete crack approach

Abstract

The ability to model fracture propagation is critical to predict the structural response of a concrete member and possible failure mechanisms. Even for structures under normal service loads, good estimations on the overall deflections and associated stiffness are highly dependent on the onset of fracture and resulting crack pattern, both directly related with the tension-stiffening effect. With the aim of developing robust models to capture this behaviour, a preliminary numerical study is herein presented on the influence of rebar diameter in the cracking pattern of concrete beams captured numerically. Focus is first given to the performance of the numerical model and its mesh objectivity. Experimental results from concrete beams tested under flexural loads are adopted for validation. Two very distinct rebar diameters are used to assess the ability of the model in predicting the average crack opening, maximum crack opening and average crack spacing for a wide range of loads.