Life cycle assessment of the production of composite sandwich panels for structural floor’s rehabilitation

Abstract

The objective of this paper is to quantify and compare the environmental and economic Life Cycle impacts of two alternative types of composite sandwich panels for the rehabilitation of degraded wooden floors of old buildings: (i) a second-generation composite sandwich panel made of glass-FRP (GFRP) skins (or blades) and a polyurethane (PUR) foam core; and (ii) a hybrid sandwich panel consisting of a glass-carbon-FRP bottom skin, a steel fibre reinforced micro concrete (SFRMC or UHPFRM) layer as top skin, and a PUR core. This works intends to find which design alternative is more eco-efficient.Life Cycle Assessment (LCA) was the method used for the quantification and comparison of environmental and economic impacts of the studied solutions. The environmental and economic LCA of this type of construction products are presented for the first time in this paper. These LCA were completed following European and international standards.The results obtained demonstrated that, for both alternatives, in terms of environmental LCA of the production, the stage of raw materials extraction (A1) is the most influential for all the studied environmental impact categories. By comparing the two alternatives, it was found that the second panel (hybrid sandwich panel) presents the highest environmental impact. More specifically, the results obtained show that the use of SFRMC for the top skin and of carbon fibres significantly increases the environmental impact of the product. Furthermore, an economic comparison of the production showed that the hybrid panel is a more expensive alternative as well.It was found that panel a1 is better than panel b1 because, in addition to the lower cost (the production cost of the latter is 24% higher than that of panel a1), it is also more environmentally friendly at the production stage (impacts of panel b1 are between 3% and 27% higher than panel a1 in categories PE-NRe, PE-Re, ADP, GWP and EP, while the latter presents impacts between 2% and 10% higher than panel b1 in categories POCP, AP and ODP). As so, the most efficient profile both economically and environmentally is profile a1, which is composed of GFRP and PUR.