Quantification of carbon emission of construction waste by using streamlined LCA: a case study of Shenzhen, China

Abstract

Currently, the majority of the construction waste (CW) has been collected without classification and simply disposed in China. To quantify the environmental impacts and provide reasonable policy recommendations, this paper conducted an assessment for the life cycle carbon emissions (CEs) for CW based on a streamlined life cycle assessment method. Three typical CW management approaches in Shenzhen City were selected to perform the case study and comparative analysis. The results show that scenario I with low recycling rate generates the largest CEs amount by 542.56 kg for 1 ton CW, followed by scenarios II and scenario III that generate 538.61 and 483.85 kg, respectively. In addition, the results show the material embody impact is the largest contributor to CEs for CW examined, accounting for 78 % of the total amount in the overall life cycle. Analysis results also show that wood, steel and concrete wastes are the top three contributors within nine materials, with proportions of 25, 23 and 13 %, respectively. Therefore, the most effective way to decrease the CEs of CW is minimizing the generation of CW, since the CEs of the majority of waste are not sensitive to alteration of treatment methods or recycling rate.