Engineer Steve Merritt explores the challenge of decarbonising concrete and cement production.
Today we have two Cs for the price of one! Concrete and cement production is responsible for, on average, 8% of global emissions. However, concrete has been used for millennia and is an integral part of construction infrastructure – it is here to stay. This doesn’t mean we shouldn’t seek to improve it however!
In Britain, 95% of concrete used is prepared within the country, and the sector has seen a 53% reduction in carbon emissions related to its production since 1990. In the UK, concrete and cement production only contributes to 1.5% of our annual carbon emissions. To achieve Net Zero however, we need to turn 1.5% into 0%. To achieve this we will need a multi-angled approach and to consider the materials applied, to ensure they remain functional for their intended life cycles.
The first component required, to reduce UK cement emissions is carbon capture, storage and usage (CCUS). CCUS is an umbrella terminology, but includes the use of polymeric filters to capture cement flue gas. Application of this technology in the UK is predicted to reduce UK emissions from cement by a further 60%. The challenge faced for asset integrity, however, is ensuring that the filters used will be able to withstand the heat and chemical composition of this flue gas.
Whilst reducing emissions from production is key, another significant carbon emitter in concrete is the energy used in maintain routine inspections and maintenance. An approach that could help overcome both these challenges is the addition of self-healing microcapsules to generic cement mixes. These produce an advanced material that is capable of healing small cracks and fissures. This healing mechanism functions autonomously, reducing the demand for inspection and maintenance, prolonging product life and reducing upkeep costs – a desirable outcome for any asset integrity manager.