Cemfree activates 95% ground blast furnace slag (GGBS) producing an ultra-low carbon alternative to concrete mix designs that traditionally use Portland cement. For over 100 years GGBS has a proven track record of significantly increasing the durability of concrete.
Portland cement (OPC) generates 913kg of C02 for each tonne of finished product. It accounts for around 5-8% of total CO2 emissions in the form of greenhouse gases, making it the third highest man-made producer of CO2 after transport and energy generation.
GGBS has long been considered to hold the key to future significant reductions in concrete’s carbon legacy. While modern advances have gone some way to replacing OPC content, Cemfree has seen its complete removal in concrete mix designs. This has led to a significant reduction in the embedded CO2 of concrete.
Although a landmark in materials innovation, Cemfree has all of the structural characteristics of traditional concrete but is more durable, more sustainable, has a lower water demand and most importantly utilises the same production techniques, design and installation principles, and delivery infrastructure. This makes its adoption extremely simple without the need to invest in new equipment or change working practices.
Already recognised by Shell in the form of a winner of the Springboard Awards, Angus Gillespie, Vice President for CO2 at Shell commented: “Shell Springboard celebrates the inventiveness of companies in the face of big challenges from climate change and the rising demand for energy. David Ball Group embodies this idea to the core."
1. Durability - Greater long-term durability than CEM1 and blended mixes.
2. Embedded CO2 - A reduction in carbon legacy of the binder component of concrete per m3 from approximately 312kgs/m3 to 31kgs/m3.
3. Reinforcement - Reduction in reinforcement steel (no requirement for thermal crack control).
4. Water - Lower water demand.
5. Thermal Mass - More thermally efficient than traditional concrete.
6. Significantly reduced requirements for joints - Reduced shrinkage enables engineers to design elements outside of conventional aspect ratios, significantly reducing the number of joints overall in a structure.