A new method for probabilistic circular economy assessment of buildings. (1st October 2022) - Lei, Haoran
Abstract: Circular economy (CE) is increasingly applied to support circular and sustainable development of buildings and infrastructures. To effectively monitor the implementation of CE, a unified assessment procedure is in urgent need. This paper aims to develop an overall CE index for probabilistic CE assessment of building materials. Models for material circularity and sustainability are established. The proposed overall CE index is demonstrated in a case study of two buildings made of cross laminated timber (CLT) and reinforced concrete (RC), considering multiple uncertain variables in different end-of-life scenarios. It is found in this paper that the circularity and sustainability indexes can facilitate the standardization of CE assessments and align them with existing limit state design codes for structural safety, e.g., Eurocodes. Results of the case study suggest that the CLT building has significant lower probability of unsatisfactory CE performance over RC building in terms of material circularity indicator, embodied energy and carbon emission. The paper concludes that the overall CE index can integrate reliability methods with CE assessment effectively. Highlights: The probability of unsatisfactory circular economy performance is quantified by considering various uncertainties. An overall circular economy index is developed to integrally assesses material circularity and sustainability. A uniform integration framework is proposed to combine reliability theory with circular economy assessment. The overall index of cross laminated timber building (1.77) is higher than that of reinforced concrete building (0.03). Cross laminated timber building has advantages in terms of material circularity indicator, embodied energy and carbon.