Cemex is now testing a form of processed household waste called Climafuel at its Rugby plant. Sustainability director Dr David Evans explains: "Waste disposal outfits like Biffa treat and stream the waste, taking out compostibles and metals, and end up with four streams, one of which is Climafuel. It’s mainly paper, plastic, low chlorine materials, wood, carpet. It’s a dry fuel, with approximately two-thirds the energy value of coal, but is considerably cheaper."
The UK is also lagging behind Europe in its efforts to develop alternative cement products. Although this, says Evans, is down to the "conservative nature" of the UK construction market. "Customers here have wanted pure cement, or cement containing at least 90 per cent clinker, whereas in Holland they’ve got down to just 60 per cent," he says in a report in Contract Journal.
Cemex has added two blended cements to the pure cement (CEM I) it already produces: CEM II, launched in February, which contains fly ash and CEM III, which contains blast furnace slag. The latter is the best blend, according to Cemex. The challenge for Cemex and other cement producers is to sell these products to UK firms, though as a spokesman points out: "One advantage of most cement producers being part of multinationals is that we can use our experience abroad to educate the UK market."