Expanding the waste stream

Originally established as a transport company operating in the construction sector by current managing director Philippe Clamens' father in 1954, Clamens S.A became one of the very first French demolition waste recyclers when it began processing concrete demolition waste in 1987.

Today, Clamens' C&D waste activities are substantial - operating from its Villeparisis base, it process a total of 800,000 tonnes of material a year, including 500,000 tonnes of concrete rubble, resulting in a turnover of €2.5 million, of which €1 million is made from the sale of recycled materials. All ferrous and non-ferrous metal is separated from the concrete using excavator-mounted attachments and segregated and recycled. The concrete is then crushed on site to produce road-fill materials, while any sand is re-used in the production of new concrete. The company is proud of the fact that it routinely recycles 100% of the material it receives. At Villeparisis, it operates a mix of Hitachi (a ZX160W-3 and a ZX350LC-3), an O&K RH9LC and Caterpillar excavators, a ZW310 Hitachi wheel loader and two Cats (a 325 and a 980G). Crushing capability is provided by a Hazemag fixed crushing plant.

France as a nation currently recycles 63% of all concrete waste annually, with recovered concrete from construction and demolition waste predominantly used for fill on roads and new buildings, although if of sufficient quality it can be re-used in the production of new concrete.

But there are other sources of concrete waste that can offer opportunities and by 2005, Philippe had expanded Clamens' activities to include processing concrete sludge, a waste product from concrete manufacture, making it the first company in Europe to do so. Normally this sludge goes to landfill but its high alkaline levels makes it a hazardous substance to dispose of in this way.

Philippe said: "one day, a truck brought a load of concrete sludge to our site and we discovered that there was quite a bit of gravel and sand as well. I thought we should find a way to recover these materials as well." He went on say that normally the sludge is made up of 43% sand, 31% gravel and 26% fine gravel. Today Clamens is still the only company in France that has a permit to recycle this material, with its main customers being Lafarge, Unibeton, Cemex and Holcim. According to Philippe, smaller cement manufacturers recycle their own waste products but the volumes concerned are in smaller quantities than those handled by Clamens.

Initially, it was the business opportunity that attracted Philippe to the processing of concrete sludge, but the environmental philosophy that also underlay the move has reached far into the company's day-to-day operations.

Its fleet of 54 Mercedes and Volvo on-road trucks frequently are on the road during the night to minimise fuel consumption and optimise travel times, with their drivers having been instructed in environmentally friendly driving techniques. Since 2003, these trucks have run on biofuel.

But it does not stop there. Clamens is also planning to install solar panels and wind turbines on its Villeparisis site to provide sustainable energy. The site also has beehives to produce honey and to aid in the preservations of biodiversity on the site.

Water used during the cleaning of the waste on site ends up with a high PH level, so carbon dioxide is added to the water to reduce this - 20 tonnes of CO2 is used a month, equivalent to the adsorption of 10 hectares of forest, in addition to the seven hectares of teak reforestation the company owns in Costa Rica.

Looking into the future, Philippe has plans to change its fleet of trucks over to hybrid trucks, change its fleet of excavators over to electric powered machines and change over to hybrid wheel loaders when all these models become available.