BENEFICIATION
Recycling is the most environmentally friendly method of dealing with C & D waste , ahead of landfill and incineration
Recycled aggregates will play an important role in offsetting the rising price of virgin aggregates .
Building materials make up around 50 % of materials used and solid waste generated globally , and construction and demolition ( C & D ) waste constitutes up to 22 % by mass in landfills across South Africa . If recycled , C & D waste can be a valuable source of secondary materials that can easily be reapplied , so there is no reason for it to be landfilled , particularly when there are constraints on landfill airspace . And while building rubble has been used as backfill for centuries , there are many other potential higher value applications for properly treated and classified material .
Whereas the characteristics of virgin aggregates are a known quantity , materials recycled from construction and demolition ( C & D ) waste have been altered through the addition of concrete , fines and chemicals , among other additives . This means that they have to be properly processed before they can be reused .
“ A definition of recycled aggregates needs to be obtained to increase the level of reliability of data and statistics and to encourage the possible use of recycled aggregates in the most appropriate application ,” says Nico Pienaar , director of the Aggregate and Sand Producers Association of Southern Africa ( Aspasa ).
According to Pienaar , for this to happen , and for secondary materials to become a viable product , proper quality control procedures need to be established and implemented . He says that South Africa ’ s aggregate producers are in the process of drawing up plans to help formalise the growing recycling industry . This will be a key means of reducing the impact of quarrying and construction on our environment , as well as combatting resource scarcity .
Greener pastures
Recycling is the most environmentally friendly method of dealing with C & D waste , ahead of landfill and incineration ( Ortiz et al , 2010 , in Ulubeyli et al , 2017 ). This is an important consideration given the growing focus on green building and sustainability . Limiting the amount of material in landfills is also a priority , not only because of legislative requirements , but also because of land availability .
GreenCape is a non-profit organisation established in 2010 by the Western Cape Government to support the development of the green economy in the region . It works with businesses , investors , academia and government to help unlock the investment and employment potential of green technologies and services . One of the areas that GreenCape is currently focusing on is the recycling and reuse of builders ’ rubble . According to the organisation ’ s 2016 industry brief Builders ’ rubble : opportunities in processing and application , there is growing
QUARRY SA | MAY 2017 _ 23