A low carbon concrete alternative set to change the construction landscape

In recent years, concrete has come under fire for high carbon emissions and low environmental sustainability. Concrete’s high embodied carbon is mostly due to the processes involved in the manufacture of cement and to a lesser degree, the energy used to process of aggregates.  The final piece of this is the transportation of all of the materials to create and deliver the finished product. 

But the construction industry is innovating at a rapid pace, with sustainability top of mind for architects, designers and their clients. A drive for low carbon alternatives has resulted in innovations in the sector, including Allied Concrete’s newly launched low carbon concrete product, Ecrete, which is set to change the landscape of concrete construction in New Zealand. 

Allied Concrete National Key Account Manager Nick Gifford says Ecrete essentially meets or betters the performance of normal concrete in most construction applications, but contains less cement. 

"Ecrete incorporates a cement replacement that effectively reduces the embodied carbon content in concrete, offering a substantial decrease ranging from approximately 10% up to an impressive 75%."

A portion of cement is replaced by Supplementary Cementitious Materials (SCMs) such as ground granulated blast-furnace slag (GGBS), which is a waste by-product from steel manufacturing.

"By making the conscious decision to replace standard concrete with Ecrete, individuals constructing with concrete can make a remarkable impact from a carbon standpoint."

The Ecrete range offers various levels of carbon reduction, and comes in standard 10%, 20%, 30% and 40% reductions. These are the most commonly used grades for Allied Concrete's residential clients. 

“If a client wants a higher level of carbon reduction for a particular reason, we have Ecrete Plus which is a bespoke mix that can reduce carbon by 50% - 75%."

When Ecrete is combined with Allied Concrete’s SuperSlab Plus (the raft slab system incorporates edge insulation and can include recycled pods as an alternative polystyrene pods), it creates a foundation solution that can contribute to making a new build much more sustainable.

“The beauty of it is that you’re using the edge insulation to reduce the amount of thermal energy lost to the environment as well as incorporating recycled plastic waste which has its own environmental benefits.  Basically you use less energy to keep warm.   

Allied Concrete is one of two major suppliers of concrete in New Zealand, with 48 concrete plants and 350 trucks across the country, which means as Ecrete is adopted by architects and homeowners, carbon emissions from concrete are set to reduce. 

“We have already used Ecrete in the Auckland and Christchurch markets just to make sure that we're happy with how it performs and the consistency of the product. We’ve had great feedback from clients, and we are already starting to see specifications come through.”

When it comes to concrete treatments and oxides, Allied Concrete has done extensive testing in partnership with coloured concrete specialist PeterFell to ensure colour oxides perform the same as they do with normal concrete. 

“After a lot of testing, we can safely say that if we put oxide into Ecrete (e10-e30), it is the same colour as it would be if added to normal concrete.”

Gifford says Ecrete performs in the same way as normal concrete, and can be used from foundations, to structural and decorative elements, and is just as versatile. 

“You can make a reasonably significant difference in your carbon footprint by making a really easy decision to say, ‘I'm not going to use normal concrete in my project, I'm going to use Ecrete’.”

Learn more about Allied Concrete’s Ecrete.