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Topic-: Recycling of concrete aggregate
Presented by-: Saurabh. L. Gundecha
Guided by-: Prof. Pujari
KJCOEMR
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 setting.
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 location.
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.
THANK YOU