Shear transfer in fly ash-concrete with electric arc furnace aggregates

This work experimentally evaluates the friction shear behavior of Electric Arc Furnace (EAF) concrete, compared to its reference counterpart made with natural aggregates only. For this scope, two concrete mixes were casted, both containing a blended cement with 30% of fly ash to improve their sustainability. For each mix, other than analyzing the main mechanical properties (compressive, tensile strength and elastic modulus), push-off specimens were tested to obtain the shear strength, failure modes, stress-slip and stress-crack opening curves. The results obtained here clearly identify an enhancement of the shear strength τ of EAF concrete compared to the reference, even though the relation between τ and concrete tensile strength fct is similar between the two concretes. Results are also compared with ones in literature, dealing with ordinary and recycled aggregate concrete (RAC). Further, existing models from both designing codes and literature were applied to the experimental results, obtaining conservative predictions in all cases. The safety margin for the EAF concrete was found to be higher than for the reference concrete.