The carbon footprint of normal and high-strength concrete used in low-rise and high-rise buildings

To reduce the mass of CO2 released into atmosphere by the construction industry, the performance strategy can be adopted. It is based on the use of High-Strength Concrete (HSC) in alternative to Normal-Strength Concrete (NSC). Such concretes are herein considered to design the reinforced concrete structures of three buildings, having 14, 30 and 60 floors, respectively. For each building, the structural analyses, carried out for four classes of concrete (i.e., C25, C40, C60 and C80) in accordance with Eurocode 2, provides different dimensions of the structural elements. In other words, the amount of CO2, released in the atmosphere due to the production of the structural materials, is a function of both concrete strength and height of the building. As a result, the minimum impact of low- rise buildings occurs when the structural elements are made with NSC. Conversely, only when HSC is used to cast the structural elements of tall buildings, can the carbon footprint be effectively reduced.