LCA of three structural solutions of a building in the University of Aveiro

Abstract

The world is facing an environmental crisis requiring more sustainable buildings. Sustainable construction has three vital columns, which are environmental, economic and social aspects. This work has focused on the first aspect, using Life Cycle Assessment methodology (LCA) to calculate the environmental impacts of the construction materials. However, LCA has some barriers when it is applied in construction, not allowing it to be widely and practically used in a common building design. This study aims to use LCA to evaluate the potential environmental impacts of three structural solutions (mixed, steel and reinforced concrete) in a Cradle-to-Cradle perspective, considering manufacturing, transport, maintenance and disposal phases. Moreover, it aims to compare two life spans: a 50-year life span and a 100-year one. In fact, designing 100- year life span building requires materials with higher resistance and higher environmental impacts than 50- year design, according to E464. Therefore, this work analyses whether the 100-year design could compensate the 50-year design, particularly when the 100-year design needs maintenance once, while 50- year design requires maintenance twice. This compensation analysis is verified using sensitivity analysis of the maintenance actions of the concrete, since the concrete has large environmental impacts and it could be maintained throughout replacing the cover layer at the end of the building life cycle. LCA is applied using SimaPro, since it is an advanced LCA tool. The work concludes that the concrete is environmentally more sustainable than the other two structural solutions, recommending using recycled steel in constructing future buildings. Moreover, the sensitivity analysis highlights the need for uncertainty treatment that could be through (i) finding national database that reduce the uncertainty and (ii) finding more sufficient maintenance actions avoiding using materials with high environmental impacts.