New cement could dramatically reduce building industry’s carbon footprint

© Tecnalia

Pre-fabricated building products based on new low-CO2 Belite-Ye’elimite-Ferrite cement binders offer low embodied energy, high performance, efficient insulation and a reduced carbon footprint.

Concrete is the most widely used man-made material on Earth, with an annual consumption of around 10 billion m³. Moreover, CO2 emissions from its fabrication account for around 5 % of worldwide anthropogenic green house gas emissions. The ECO-BINDER project promises to greatly reduce this carbon footprint, and in the process transform the concrete and building industries.

ECO-BINDER, which started in January 2015 and runs for four years, aims to develop a new generation of concrete-based construction materials and pre-fabricated building envelope components with more than 30 % lower embodied energy, 20 % improved insulation properties and 15 % lower cost than the current solutions that are based on Portland cement.

‘We’re The project is demonstrating that Ordinary Portland Cement or (OPC) and OPC-based concrete products based on it can be replaced with new ones based on the Belite-Ye’elimite-Ferrite or (BYF) class of low-CO2 binders, without compromising on quality or cost,’ says Mr. Frederico Meneghello, project coordinator and [Technology Intelligence title Area Manager] at D’Appolonia S.p.A.

Why BYF technology is superior

In BYF technology, the superior early age strength contribution of calcium-sulfo-aluminates is combined with durability provided by belite. Preliminary life-cycle assessment calculations show that BYF CO2 emissions are lower than those of Portland cement due to the lower calcium content of the raw materials (less limestone usage); a lower clinker burning temperature of around 1250 – 1300°C; and lower energy consumption for grinding. These factors result in a significantly lower embodied energy than OPC cement.

The new building envelope solutions will also integrate multiple functions in a single product package. They promise higher performance in terms of acoustic insulation/absorption, fire and mould resistance, dimensional stability to avoid air or water leakage, and the optimisation of indoor air quality. In addition, they will offer multi-functional surface properties such as thermal reflection, anti-stain, anti-bacterial and self-cleaning, depending on the finishing technologies applied.

To establish a reasonable basis for comparison with Portland cement, ECO-BINDER’s researchers have started by reviewing the regulations and norms in the construction industry.

‘We want to Their aim is to see whether if they we can use existing norms, which are based on Portland cement, or whether they we will need to establish new norms,’ says Mr. Meneghello. ‘The ultimate goal is to ensure that a reasonable comparison can be made and that standardisation will not present a barrier to adoption of the new products.’

Demonstrating that it works

To demonstrate the effectiveness of the new technology, ECO-BINDER is building small demonstration houses at sites in Spain, the UK and Romania. The houses all have the same dimensions and the same exposition to the sun, while their different locations enable ECO-BINDER’s researchers to test the impact of climatic conditions. Temperature, humidity and other variables will be monitored over the course of at least an entire year in order to examine seasonal influences as well as durability. Similar structures built using Portland cement will be monitored on the same sites in order to compare the two technologies side-by-side.

As pressure builds to reduce buildings’ carbon footprint, existing structures will need to be renovated. Retrofitting them with ECO-BINDER’s pre-cast components could be more environmentally friendly and cost-effective than applying new cement. At the same time, the new cement developed in ECO-BINDER could be used outside the pre-cast sector, too.

‘We think that ECO-BINDER’s technology could eventually even replaceing the OPC technology for fresh cement as well,’ says Mr. Meneghello.