Embodied energy and carbon footprinting of concrete production and use

As the issue of climate change is becoming more prevalent, an emphasis has been placed on the use of building materials which are deemed ecologically sustainable. Given the large quantities of concrete used in construction, much has been done to reduce the ecological footprint by using alternative fuels in cement production, cement replacements and recycled aggregates. This paper outlines the current state of concrete production in the United Kingdom and Ireland, examining items such as most common constituents, production process, mix types and strength classes. The embodied energy and carbon associated with the manufacture of concrete, and subsequent use in its most common application, ready-mix concrete, were examined. To ensure that the research may be as useful as possible to practising structural engineers and concrete specifiers, the methodology presented is based on the recommended limiting values for composition and properties of concrete under the varying environmental exposure classes as per BS 8500- 2:2006. Designed concrete mixes suitable for the varying exposure classes were obtained and, based on figures from primary and secondary sources, the embodied energy and carbon of concrete production calculated. The output of the research, an interactive spreadsheet, allows users to specify and compare concrete mixes in terms of embodied energy and carbon.