Singapore consumes large volumes of concrete to sustain its growth in construction. To comply with its Green Mark Scheme, it is necessary for Singapore to take action in consuming concrete products with lower carbon footprint. This study quantifies and suggests alternatives for reducing the embodied energy and environmental impacts of cement and aggregate consumption in concrete products being utilized in Singapore. A cradle-to-gate life-cycle assessment methodology is considered to quantify the life-cycle inventory of cement and aggregates based on the current trading volumes of these concrete materials imported to Singapore. The cradle-to-gate system boundary includes raw materials extraction, production processes, and transportation of raw materials to production facilities as well as transportation of end-products (cement and aggregates) from the production facility in the importing country to the Port of Singapore. Geographical system boundary covers the neighboring countries that export cement and aggregates to Singapore. Life-cycle inventory results include an inventory of environmental exchanges (energy as input and major air emissions as output) for the functional unit within the defined product system. In this study, results are first demonstrated as per unit weight of cement and aggregate imported to Singapore. Following the calculation of life-cycle inventory results per unit weight of cement and aggregates, embodied energy and global warming potential of a concrete mix normalized with respect to strength are compared for two scenarios. The first scenario represents the Singapore's current trading volumes while the second one is based on cement and aggregate imports from Malaysia which due to its close proximity to Singapore and efficient production technologies and greener fuel mixes results in a reduction in both global and regional impacts compared to the Singapore's current trading conditions. By importing cement and aggregates from Malaysia instead of the current trading conditions global warming potential and embodied energy of a high-strength concrete mix can be reduced by 11% and 31%, respectively. (C) 2016 Elsevier Ltd. All rights reserved.
