Measuring the Embodied Carbon Content of Concrete Paving

This paper summarises the outcomes of a PhD research project by Richardson (2009) to measure the embodied carbon content of concrete paving and to reveal the barriers to its accurate measurement. This is a current area of research due to the concerns arising from the anthropogenic emission of carbon dioxide which has been identified as a key cause of climate change. The work was carried out in co-operation with a major manufacturer of concrete paving revealing the practicalities of energy auditing within an existing factory using its unmodified infrastructure, methods of energy metering and recording. The work involved identifying all of the energy inputs involved in the manufacturing process during a financial year. The auditing boundaries were restricted to the main manufacturing facility and its immediate suppliers of raw materials commonly known as cradle to gate. The energy applicable to the paving material had to be apportioned from site wide energy usage. The energy used to supply the raw materials and operate the manufacturing facility was then converted to an amount of carbon dioxide released using standard conversion factors. The barriers to accurate auditing were identified and an embodied carbon coefficient for the raw materials and finished product determined. The embodied carbon contents that were determined differed from those found in the national database. A number of factors are identified that could have contributed to this and suggestions for further research made. Introduction It is now widely accepted by the scientific community that the release of carbon dioxide (CO2) into the atmosphere from fossil fuel based energy use is a major contributor to climate change. In the United Kingdom (UK) the construction and operation of buildings has been identified as supplying almost half of the CO2 discharged into the atmosphere each year (Drummond, P., & Ekins, P. 2016). It can be seen then that reducing the energy used to construct and operate buildings is key to reducing the overall UK CO2 output. To date, the main focus has been given to reducing the energy used in the operation of buildings. In the UK this is primarily consumed by space and water heating systems but also includes other building services installed in the premises including, lighting, fans and pumps and in some buildings air conditioning and mechanical movement systems. Much legislation has recently been implemented to reduce the operational energy use of new buildings. This includes changes to Part L of the Building Regulations (Department for Communities and Local Government 2016) which includes elements of the EU Energy Performance of Buildings Directive (European Union 2010). The aim of this legislation is to reduce the CO2 output arising from fossil fuel energy