After nearly 30 years as an architect, Guy Thompson joined The Concrete Centre as Head of architecture, housing and sustainability.

ince the announcement of the UK Government’s 2020 target for reducing carbon emissions, the decision making processes in design and construction have seen some dramatic changes.

The 2014 Sustainability Performance report, due to be launched at the Concrete and Masonry Pavilion at Ecobuild 2016, details industry progress in reducing the overall CO₂ emissions associated with concrete production. In the seven years since the industry published its first report, there has been an 11% improvement in energy efficiency and a 13% reduction in carbon intensity. 2014 data resulted in 76.3kg of CO₂ per tonne of concrete, based on the standardised mix. The target for 2020 is to reduce this figure further to 71.8kg of CO₂ per tonne, which equates to an overall 30% reduction from the 1990 baseline.

Concrete is a mix of materials, its CO₂ emissions are affected by their production, from processes such as cement manufacture, transportation and a range of other criteria.

The cement sector is a major component of the embodied energy in concrete, and have continued to achieve improvements in energy efficiency. The embodied carbon of cement has been reduced through the use of waste-derived fuels. Some 44% of the fuels the cement industry use are derived from waste or by-products reducing the use of carbon intensive fossil fuels.

The embodied CO₂ can be further lowered by the use of cementitious additions derived from other industries. These include fly ash from power stations and ground granulated blast furnace slag (GGBS) from the iron and steel industry. In 2014, 26.2% of all cementitious materials used were by-products; the target set for 2020 is 35%.

The industry has a very clear vision to reduce both embodied CO₂ within its own manufacture and operational CO₂, through the sustainable use of concrete products in the built environment. In 2008, the UK concrete industry committed to a Sustainability Construction Strategy and a key commitment was to contribute to a low carbon built environment. The strategy also sets targets, for indicators relating to waste reduction, responsible sourcing, water, wellbeing, and biodiversity amongst others.

The original initiative focused more on those aspects that were within the concrete industry’s control – in other words, the cradle-to-factory-gate impacts of production. In 2012, in response to the European Commission’s drive towards greater resource efficiency, the UK concrete industry broadened its strategy to include the impact of the material post production.

Now, this has extended still further with a series of resource efficiency action plans (REAPs), involving close collaboration with stakeholders, contractors and those responsible for projects to the end of service life with the objective to deliver a more holistic approach to measuring and demonstrating whole-life product stewardship.

In 2014, significant progress was made on how to measure and agree targets for water consumption, with the publication of the Mineral Products Association (MPA) Water Policy. The Policy sets out three aims:

• Minimising water consumption
• Prioritising use of the most sustainable water sources
• Protecting the water environment

Implementation of the Water Policy will improve understanding of the amount of water consumed and demonstrate where measures have been implemented to reduce consumption, ensure the use of the most sustainable water sources and maintain water quality.

Based on this, the Sustainable Concrete Forum is developing specific indicators for the measurement of sustainability performance and target setting, as per the Concrete Industry Sustainable Construction Strategy 2020 commitment made in 2012.

The concrete industry is currently investing in generic Environmental Product Declarations (EPDs) and BIM guidance, to help designers harness the sustainability credentials of concrete on a credible basis from the earliest design stage of building and infrastructure projects. The Mineral Products Association published the first of these in 2013, declaring the lifecycle environmental impact of UK-factory produced cement. This has paved the way for the production of generic EPDs for precast concrete products, ready-mixed concrete and mortar, which will provide a sound basis for project environmental or carbon assessments.

With regard to BIM, Government legislation for implementation of level 2 for government projects in 2016 has galvanized development and implementation.

For products, the formatting of BIM product data templates (PDT) is key. Each PDT aims to anticipate the information sought by every party – from specification through operations to decommissioning and replacement. When a manufacturer completes a PDT it becomes a Product Data Sheet (PDS) – a ‘digital’ description of the product. It is envisaged that some or all EPD data fields will become part of PDTs and hence PDSs – the digital description – will contain environmental impact data.

The Concrete Centre provides guidance to enable designers to specify sustainable concrete whilst recognising that embodied carbon reduction is but a small part of the solution for the provision of sustainable construction when measured over its lifetime, when taking into account energy savings from thermal mass and the climate change protection provided.

For more information, guidance from The Concrete Centre and product manufacturers will be available from the Concrete and Masonry Pavilion at Ecobuild 2016.