LOCOWAG - low carbon concrete for use within aggressive ground

Global demand for concrete, the primary volume construction material for most structural applications, continues to grow. The majority of concrete relies on use of Portland cement (PC) as the only economic binder meeting performance and durability requirements under the wide range of conditions in which concrete is used. However, **PC manufacture accounts for c.5-8% of global CO2 emissions** so alternatives are urgently required.

50% of ready-mixed concrete is used in foundations below ground and must be carefully designed to resist chemical attack (e.g. sulfates as described in BRE Special Digest 1, Concrete in Aggressive Ground), often increasing the amount of cement used in the foundation and consequently the environmental impact.

LOCOWAG will develop and assess (via laboratory testing and site pilots) innovative concrete formulations in which PC is replaced with novel 'Alkali-activated cementitions material' (AACM) 'Cemfree' (manufactured by UK SME DB Group (DBG)). Cemfree has potential to reduce the CO2 associated with a concrete foundation relative to PC. Cemfree concrete is also more resistant to chemical attack, derisking the use of concrete in the ground. LOCOWAG will enable DBG markets to grow. It will also unlock markets more widely for AACMs in critical construction applications, creating a high- volume market for AACM (and low carbon cement manufacturers more widely). However Cemfree (and AACMs generally) are not covered by existing concrete standards and therefore unable to be widely used.

The project will:

1. Develop, assess and demonstrate Cemfree-based concrete formulations meeting user needs for foundations (buildings and infrastructure).
2. Demonstrate and assess use of Cemfree in piling to de-risk adoption.
3. Carry out laboratory tests to assess durability of Cemfree-based concrete formulations in sulfate-rich conditions (and other key performance characteristics), and compare with those of PC-based and other AACM-based concretes.
4. Assess and address barriers to market (especially the need for industry-wide guidance and acceptance, such as BS8500 and BRE SD1).

The 2-year project will be led by DBG, together with a supply chain orientated consortium piling contractor (J Murphy and Sons, (JMS)), precast pile manufacturer (Centrum). BRE (an impartial centre of expertise that also develops application guidance for the construction industry) will carry out laboratory testing essential for updating guidance and support DBG in project management. We will work with standards bodies (BSI, Green Construction Board) to address key standards-related barriers to market uptake. An Industry stakeholder group (regulators, manufacturers, end-users) will help guide outputs (e.g. BRE documents) and address barriers to mainstream use.