Company Announcement - Massive quantities of construction and demolition waste are being dumped in landfills without the recycling of such a potentially valuable building material being considered, says Bryan Perrie, MD of The Concrete Institute. Perrie says significant volumes of C&DW – including large volumes of concrete - are ending up in municipal solid waste landfills in South Africa. “There is currently growing concern worldwide about this wastage of materials such as concrete, wood, gypsum, metals, bricks, glass, plastics, and salvaged building components like doors, windows and plumbing fixtures. The waste debris usually originates from the demolition of buildings or civil infrastructure - could also contain hazardous materials such as lead, asbestos or even radioactive materials,” he stated.

“Yet there is tremendous potential to recycle so many elements of demolition waste, particularly concrete, which can be crushed and reused in construction projects instead of occupying valuable landfill space.” Perrie says the European Union, for example, has identified C&DW as a priority waste stream, recognising the high potential for the recycling and re-use of such debris, particularly concrete. C&DW annually amounts to around 510 million tons (equivalent to 30% of all waste generated) in Europe. “In the USA, C&DW totals about 325 million tons per year, and in Japan, 77 million. C&DW totals in countries such as China and India, which together produce about 50% of the world’s concrete, must be substantially higher.  In Europe, the EU has decreed that aggregates derived from C&DW in roads, drainage, and other construction projects, must be recycled. In fact, the technology for the separation and recovery of construction and demolition waste is now well established in European countries, readily accessible, and generally, inexpensive.

“In the USA, the Federal Highway Administration actively promotes the recycling of concrete from pavements and roads, and such recovery programmes are now in operation in just about every state in America. Uncontaminated concrete pavements can serve as substitute for most natural aggregates. The economic benefits are enormous. In Anaheim in the USA, 700 000 tons of concrete were reused on a freeway project, providing a cost saving of US $5 million. Similar economic benefits of concrete recycling have been experienced in Melbourne, Australia, where 15 000 cubic metres of concrete were recovered for the construction of the city’s Western Link, yielding cost savings of over Aus $4 million,” Perrie asserts.

He says controlled demolition, incorporating a sorting system which would separate reusable elements on site - and also taking the quality and history of the concrete waste into account – is a vital component of sustainability. All concrete deemed suitable for recycling should be used for new concrete production. A properly structured demolition waste recycling programme would also create new employment opportunities and reduce the exploitation of natural resources. Perrie also believes that more attention should be paid to the re-use and recycling of building materials such as concrete at the design stage to more actively promote sustainability in the construction industry.