A sustainable approach to the design of reinforced concrete beams

Reinforced concrete (RC) structures are generally designed to satisfy the ultimate and the serviceability limit states. In the specific case of RC beams, the current building codes only indicate how to comply with both the bearing capacity and the limitation of deflection, without considering the reduction of the environmental impact. Conversely, in this paper, sustainability is taken into account in addition to the traditional limit states used to design beams in bending. As more eco-friendly cement-based mixtures can be attained by optimizing the performances and applying material substitution strategies, concretes made with fly ash are investigated herein. According to the Eurocode 2 requirements, a new procedure is proposed to design RC beams made with this kind of concrete. As a result, we show that the most efficient RC structures must be cast with high strength concrete systems containing the largest substitution rate of cement with fly ash.