Environmental sustainability of precast and cast-in-situ concrete structures: a case-study comparison based on built supermarket facilities

Environmental sustainability is assuming a growing role in the strategic plans of several countries worldwide. In order to switch to more sustainable solutions in the construction field, many researchers and efforts are focusing on the material level, mainly concerning solutions aimed at partially or fully replacing the most impacting components with alternative or recycled solutions characterised by a lower carbon footprint or a higher durability, in view of a life-cycle assessment. Alongside these positive efforts, another instrument to reduce the environmental impact of construction materials, often less tackled by researchers, is reduction of material consumption by structural optimisation, often ensured by innovative technologies possibly employing high-performance materials that might even have, assuming same volume, higher impact than traditional ones. This concept is analised in the present paper by comparing the computed environmental equivalent carbon footprint of two similar single-storey supermarket facilities, designed and built in the Po valley, Northern Italy, with different technologies: precast and cast-in-situ concrete. Having at disposal the final consumptive volume of materials employed for both buildings concerning the superstructure frame without cladding, the comparison based on Global Warming Potential (GWP) certified by material producers, computed per square metre covered, allowed to evaluate the actual impact of the structure of the two solutions. Moreover, the environmental-related benefits provided by the replacement of the most impacting components (steel and cement) with alternative environmentally friendly solutions further allows to quantify and target the most effective strategies to enhance the sustainability of structural bodies.