Auditing carbon reduction potential of green concrete using life cycle assessment methodology

The production of concrete in its traditional form have reported a notable impact on the environment in terms of resource depletion and the carbon footprint it generates in the entire life cycle. To reduce these impacts, the ‘Green Concrete’ concept is at focal point of research in the construction industry. The advantage of resource conservation of ‘Green concrete’s is evident from usage of industrial by-products like fly ash, blast furnace slag, silica fume etc. as alternative binder materials and recycled wastes like construction and demolished waste and other industrial wastes as aggregate fillers. However, the quantification of environmental impact of such concretes in terms of most crucial emissions, like CO2 emissions in an objective way would confirm the eco-friendly face of ‘Green concrete’. Life cycle assessment (LCA) is one of the most trusted tools to arrive at carbon score of such green concrete. This paper presents a step-by-step procedure of estimation of carbon footprint of a green concrete considering all possible phases of the life cycle of concrete including the post use phase. The conclusive findings from available literature for different types of ‘Green concrete’ are also presented to reflect the environmental advantage/disadvantage. The effect of system boundary, carbon uptake and allocation of impact are also discussed with reference to the results available in the literature.