Life cycle assessment of alternative building floor rehabilitation systems

The aim of this study is to quantify and compare the environmental impact from cradle-to-gate of different systems for building floor rehabilitation. The Life Cycle Assessment (LCA) method was used for the evaluation of the potential environmental impact of the production of each floor system in eight categories and a monetisation method was used for the weighting of the results and for their expression into one single indicator. Five functionally equivalent (from a structural standpoint) systems were assessed, including: (i) traditional solutions, such as timber floors and reinforced concrete (RC) slabs; (ii) less conventional solutions, such as beam-and-block and steel-concrete composite slab systems; and (iii) an innovative glass fibre reinforced polymer (GFRP) sandwich panel system. The environmental impacts of these systems are compared in this paper for the first time. It was found out that timber is the most environmentally friendly solution, since it presents the lowest total values in all environmental impact categories (under 1% of the impact of the solution with highest impact in each category, RC or GFRP), except for primary renewable energy consumption, for which the RC solution presents the least consumption. On the other hand, it was found out that: the steel-concrete composite floor is the least environmentally friendly solution in abiotic resource depletion; the RC solution is the least performing option in terms of global warming potential and ozone depletion potential; and the GFRP system presents the worst behaviour in five environmental impact categories - non-renewable energy consumption, photochemical ozone formation potential, acidification potential, eutrophication potential and Eco-costs. However, if the most important inefficiencies identified during the production of the latter floor system are at least partly amended, its impacts would be substantially reduced, particularly regarding the Eco-costs indicator, which considers four environmental categories at once - in that case, the RC solution would become the worst solution and GFRP sandwich panels would have an aggregated result of 80% of the RC. The final part of the paper presents a qualitative assessment of the gate-to-grave performance of the different solutions.