Environmental Impact of Cold-Formed Z-shaped Steel Purlins

Abstract

AbstractIn an effort to mitigate climate change, the construction industry is moving toward a more responsible approach regarding production and design methods. The environmental impact of a structure must be reduced from the design phase by using reliable design approaches and choosing the production and construction processes that minimise as much as possible the carbon footprint. The purlins are components of the roof structure and their scope is to transfer the roof loads to the rafters. An efficient design of purlins is generally achieved by using cold-formed steel Z-shaped profiles. Z purlins span continuously over the rafters to reduce material use through a more favourable bending moment distribution. To ensure continuity of the bending moment along the length of the structure, the purlins form overlapped connections on the supports. The focus of this research paper is to assess through the Life Cycle Assessment methodology how the design influences the environmental impact of overlapped purlins. The paper assesses the impact of higher-grade steels versus more traditionally used steel grades. Furthermore, the adoption of steel manufactured using a high content of scrap steel and energy obtained from renewable sources facilitate the reduction of the carbon footprint of the element. Using advanced finite element models, previously validated against experimental results, the purlin systems were designed to support both gravity and pressure loads.