Reducing embodied CO2
The Hanson EcoPlus concrete range benefits from the use of Hanson Regen, a cement substitute manufactured from a by-product of the iron-making industry. Replacing one tonne of Portland Cement with one tonne of Regen in EcoPlus concrete reduces the embodied CO2 by around 850kg.
- Low CO2 concrete
- No mineral extraction
- Reduced landfill
- Post-industrial by-product
- More sustainable than other cement substitutes such as Fly Ash (PFA)*
- Meets criteria for sustainable construction
Using Regen can significantly reduce the embodied carbon content of concrete, making EcoPlus a more environmentally friendly concrete option.
*The level of Regen in EcoPlus concrete can be as high as 70%, which is usually more than twice as much as other cement replacements such as PFA, which would typically be around 30%.
- Will last longer, even in aggressive environments
- Less cracking by minimising the heat of hydration in mass concrete pours
In practice, concrete will deteriorate over time so durability is essential. The factors driving this deterioration can be internal (e.g. alkali-silica reaction) or due to external aggressive environments (e.g. sulfate attacks). EcoPlus (where specified correctly) is a more durable concrete that can better resist deterioration.
Concrete embodied CO2e from Cement and Additions (kg/ cubic metres)
|CEMI||30% Fly Ash (PFA)||50% GGBS||70% GGBS|
|Total cementitious content||320||360||330||370|
|Total cement and additions CO2e||292||228||161||117|
|The table above shows the quantity of embodied CO2e from the cement and additions in a typical C32/40 concrete.|
Heat of hydration
The hydration of cement is an exothermic reaction. The use of EcoPlus concrete reduces the heat of hydration. High temperatures in concrete can generate stresses that could result in early-age thermal cracking. This cracking is known to have caused issues with some structures, so the use of EcoPlus with Regen inside is recognised as an effective solution to the problem.
Minimising heat of hydration to reduce thermal cracking is of critical importance in mass concrete pours. A bespoke mix including high levels of Regen was used successfully in the construction of The Canary Wharf Box in London. The percentage of Regen used directly affects the heat of hydration; a replacement level of around 70 per cent is recommended for large pours. A temperature reduction of up to 40 per cent can be achieved with a 70 per cent replacement level.
Where EcoPlus concretes are used in mass sections, it is not unusual to stipulate strength conformity at 56 days to better allow for the maturing development of strength.
As concrete using Regen (GGBS) benefits from lower heat generation, the product does take slightly longer to set. This is generally influenced by many factors, in particular temperature and water/cement ratio. However, an extended setting time does mean that the concrete will remain workable for longer and there will be less risk of cold joints. This is particularly useful in warm weather.
- Lighter-coloured concrete
- Aesthetically pleasing
- Safer in dark areas
Calculations of embodied carbon content of concretes have relied upon the published values found in the MPA (Mineral Products Association) fact sheet 18 (Embodied CO2e of UK cement and cementitious material).
Easy to specify and order
- Order by type of application or a bespoke solution if required
- Conforms to BS 8500 and BS EN 206-1
- Available nationwide from all Hanson concrete plants
- Helpline for professional and technical advice
- Aesthetically pleasing, lighter-coloured concrete
- Hanson is a member of the Quality Scheme for Ready-mixed Concrete (QSRMC) and all our products carry this certification