At the end of 2012 the Dutch government concluded a ‘Green Deal’ to improve the sustainability of the concrete supply chain with the organisation MVO Netwerk Beton, made up of 21 companies and 6 trade associations involved in the chain. The aim is to achieve a 100% sustainable concrete chain in 2050, with initial tangible steps being taken in the short term. In the context of this Green Deal the Directorate-General for Public Works & Water Management (Rijkswaterstaat) and MVO Netwerk Beton asked CE Delft to analyse the environmental footprint of concrete use by the Dutch construction industry, including an analysis of a number of improvement options.
In 2010 14 million m3 of concrete was used in Dutch construction and around 550 kt of reinforcement steel. From cradle to grave this concrete use had a climate impact of 3.5 Mt CO2 (1.7% of Dutch national emissions).
The analysis also encompassed the carbon emissions of energy consumption during the use phase of homes and offices in 2010. Restricting ourselves to the energy used for space heating in homes built in 2010, under the current EPC standard (*) (0.8) the climate impact of concrete use in homes is estimated to be approximately the same as that of heating a home for five years. Over a lifespan of 50 years, then, it takes roughly ten times as much energy to heat a home built in 2010 as it does to produce the reinforced concrete used to build it.
The following improvement options are discussed:
- use of concrete grade CEM III rather than CEM I
- various options to reduce the environmental footprint of cement production (biomass use, carbon capture and storage, etc.)
- use of Concrete Core Activation in homes and offices to save on space heating energy consumption.
While conducting the analysis a number of issues were noted that can lead to improvements in this analysis and in LCA assessments by other researchers:
- There is scope for improving familiarity with and general availability of environmental data on various concrete and cement grades, specifically for the Dutch situation. For the Netherlands, the much-used Ecoinvent database (available in LCA software) contains outdated information.
- There are still no specific environmental data on CEM II, CEM IV, CEM V cements and a number of CEM III grades, even though their footprints differ substantially. Further refinement of these data would therefore enable more precise analysis.
- There is currently no reporting on the particulate emissions associated with Dutch cement and concrete. To enable a full environmental analysis, such national data should be made available, so that researchers are no longer dependent on Ecoinvent.
(*) The energy performance coefficient (EPC) is an index of the energy efficiency of new-build homes, a theoretical standard of energy consumption calculated prior to construction.