Behavior of beam-column joints made of sustainable concrete under cyclic loading

This work is part of a wide study related to the structural behavior of concretes prepared by substituting natural aggregates with recycled aggregates from building demolition. In this work, recycled aggregates coming from an industrial crushing plant in which rubble are suitably treated were employed in substitution of ordinary aggregates. In order to evaluate the real-scale behavior of reinforced recycled-aggregate concrete, several beam-column joints were manufactured, then cured in open air at a temperature of approximately 20 degrees C in order to simulate the real conditions of the building site. Subsequently, they were submitted to low-cycle loading, characterized by a load history containing few cycles but having a large range of bond reversal stresses in order to simulate real structures subjected to earthquake or high winds. In this way, the ductility of joints, made of either ordinary or recycled-aggregate reinforced concrete, could be investigated and compared. The results gave experimental evidence of the suitability of recycled-aggregate concrete for structural use, although some measures in the structural design of the joint should be taken.