Allied Concrete is building on its reputation as the industry’s technical leader and has taken a range of initiatives to reduce its carbon footprint in its concrete products.

For several months, Allied Concrete has undertaken extensive research into supplementary cementitious materials (SCM), investigating the influence of replacement materials for Portland cement in order to lower the amount of embodied carbon in concrete. Using Ground granulated blast-furnaced slag (GGBFS) – commonly known as slag – or fly ash, these two SCMs allow for a smaller carbon footprint in concrete. Using slag and fly ash, the “ecrete” range of reduced embodied carbon mixes has been developed.

These ecrete mixes can reduce between 10% and 60% of embodied carbon, depending on project requirements. To keep things transparent, Allied Concrete is measuring its embodied carbon reduction relative to the Infrastructure Sustainability Council (ISC) 2020 benchmark for ready-mixed concrete.

The footprint is smaller but there’s no compromise on performance. Ecrete mixes exhibit reduced shrinkage, an increase in long term compressive and flexural strength, reduced peak temperature, and an increase in durability.

Developing the mixes to ensure they perform to a rigorous standard has required an innovative approach. For example, just for applications that require high early age strength more than 15 chemical admixtures across various manufacturers were trialled in more than 50 lab mixes alone. These tests also required significant logistical and operational challenges to be overcome and required full commitment from Allied Concrete, with help from Holcim Cement.

Recently, Allied Concrete worked with the HWR Marketing team to produce a brand for ecrete in order to bring the product to market and increase awareness of this more sustainable alternative to traditional concrete.

Ecrete is one of many initiatives across the Group that form HWR’s commitment to sustainability. Allied Concrete is at the forefront of game-changing practical implementation on this sustainability journey. It attained Australasia’s first Environmental Product Declaration (EPD) in 2014 for ready-mixed concrete, and is now leading the way in revolutionising the use of GGBFS and removing barriers to its access for concrete production in New Zealand.