Topic-: Recycling of concrete aggregate
Presented by-: Saurabh. L. GundechaGuided by-: Prof. Pujari
What is recycling? Recycling is processing of used materials
into new products to prevent waste of potentially useful material,
reduce the consumption of fresh raw material, reduce energy usage,
reduce air pollution & water pollution by reducing the need of
conventional waste disposal. In short, recycling is a key component
for modern waste reduction.
Concrete recycling When structures made of concrete are
demolished or renovated, concrete recycling is an increasingly
common method of utilizing the rubble. Concrete was once routinely
trucked to landfills for disposal, but recycling has a number of
benefits that has made it a more attractive option in this age of
greater environmental awareness & the desire to keep
construction cost down.
Concrete aggregate collected from the demolition sites is put
through a crushing machine. Crushing facilities accept only
uncontaminated concrete, which must be free from trash, wood, paper
& other such materials. Metals such as rebar, since they can be
removed with magnets & other sorting devices & melted down
for recycling elsewhere.
Why recycle concrete? Its high quality- meeting or exceeding all
applicable state & federal specifications. It provides for
superior compaction & constructibility. Its higher yield-
recycled aggregates are lighter in weight per unit of volume, which
means less weight per cubic yard, resulting in reduced material
cost, haul costs & overall project cost. It weighs 10%-15% less
than comparable virgin quarry products (concrete).
It offers a way to reduce landfill waste streams. It means
minimisation of environmental impacts in an urban quarry
Benefits There are variety of benefits in recycling concrete
rather than dumping it or burying it in a landfill & some of
them are as follows-: Keeping concrete debris out of landfills
saves landfill space. Avoids haul-off costs & landfill disposal
fees. Eliminate the expense of aggregate material imports &
exports. Increase project efficiency & improve job cost.
Recycling one ton of cement could save 1360 gallons of water,
900 kg co2. Using recycled concrete as the base material for
roadways reduces the pollution involved in trucking material.
Produce specification sized recycled aggregates at your
Uses Crushed recycled concrete can be used as the dry aggregate
for brand new concrete if it is free from contaminants. Larger
pieces of crushed concrete, such as riprap, can be used for erosion
control. With proper quality control at the crushing facility, well
graded & aesthetically pleasing materials can be provided as a
substitute for landscapping stone.
Smaller pieces of concrete are used as gravels for new
construction project. Used as foundation for road pavements. Other
applicable uses include Ready mix concrete, soil stabilization,
pipe bedding & as a landscaping material.