Bacteria-based self-healing concrete− A life cycle assessment perspective
Ismael Justo-Reinoso, Noemi Arena, Bianca Reeksting, Susanne Gebhard, Kevin Paine
Abstract
This study utilises life cycle assessment (LCA) to evaluate the environmental impact of bacteria-based self-healing concretes (BBSHCs), where non-ureolytic bacterial endospores are encapsulated in porous calcium silicate granules. Findings reveal that 1 m3 of BBSHC has an overall 85% higher environmental impact than equivalent conventional concrete, primarily due to calcium nitrate and polyvinyl acetate. Furthermore, BBSHC has a 36% larger embodied carbon footprint (120 kg CO2 eq) and a 51% larger water footprint (260 L). However, by selectively incorporating BBSHC in specific areas of reinforced concrete structures, leveraging its inherent self-healing properties to deliberately allow wider crack widths, and consequently, reduce the amount of non-structural steel needed to control early-age cracking, sustainability improvements ranging from 12% to 50% can be achieved depending on the impact category. In this regard, the embodied carbon footprint of a BBSHC-structure could be reduced by 12%, thus preventing the emission of 51 kg CO2 eq.