1. Recent Trends In
Environmental Engineering
DEBRIS-THE POTENTIAL WASTE

2. ABSTRACT
Debris, the construction waste is used as a substitute of fine and coarse aggregate
in the manufacture of hollow blocks and pavement blocks. The debris collected
from site is crushed down to the size of coarse aggregate (40-50mm size and
remaining into size of fine aggregate after screening the wood dust and sundry.
They are then mixed with cement and water and poured into a mold and vibrated to
compact and then cured for 14 days and sundried. Cost of the blocks from debris is
very cheaper than bricks and helps in saving 25-30%. It also helps in reducing
various environmental degradation promoting environmental upgradation. On
comparing with bricks also results in positive. The ultimate goal of the project is
to substitute a portion of clay brick production with recycled material collected
from the overwhelming amounts of C&D waste produced in the city each day.

3. WHAT IS DEBRIS?
Debris or Construction & Demolition (C& D) is the waste obtained in pulling
down of existing structures, bridges, concrete roads etc. consisting of bricks,
concrete lumps, tiles, cement plaster, stones, glass, sand , steel and timber.
STRATEGY OF DEBRIS:
It Is estimated that Indian construction company alone generates 10-12
million tonnes of debris annually

4. The city of Mumbai alone generates 7500 tons of solid waste per day and
debris constitutes about 30% of the whole i.e. about 2250 tons a day.( CYBC
( CIDCO-YUVA Building Center)).
The generation of Debris in the city is expected to grow at least twice due to
several infrastructural projects like metro rail, highway, mono rail and
flyovers etc.
ENVIRONMENTAL DEGRADATION:
In the absence of designated dumping grounds the debris is thrown on road
sides, Mangroves and empty plots in the city. This practice causes
environmental degradation, destroys valuable Mangroves and affects public
health.
The debris dumped on plots clogs drains during monsoon & creates
unhygienic conditions.
Dumping also helps mushrooming slums & narrowing of natural water
bodies that leads to floods.
Mangroves are unique tropical forest ecosystems found in tidal mudflats.
Dumping wastes in mangroves not only destroys their beauty and
biodiversity, but also poses serious safety risks to city as its dense
decreases.
Future debris dumps threaten to increase ecologically sensitive areas.
DAWN TO DEBRIS PROBLEMS:
One nongovernmental organization called YUVA have addressed the issue
as its social obligation and studied the subject in detail under the project
name CYBC ( CIDCO-YUVA Building Center) . Their research showed the
possibility of debris recycling to produce useful cost effective, non-
hazardous and quality building materials.
There came the innovative technology of debris recycling.

5. Debris recycling demonstration Plant at Kharghar brought the technology to
the ground and produced many types of building materials like concrete
bricks, blocks, paving blocks of various designs etc.
Their laboratory test results proved the quality of the products.
The plant is more helpful for real estate developers, Contractors,
Municipalities and Municipal Corporations, civil engineers at presentwho
faces the issue of debris disposal.
ENVIRONMENTAL UPGRADATION:
Sustainable method to reduce the effect of debris landfills thus creating eco
safe environment
Reduces hazardous and air polluting brick making industry thus Saving
valuable timber.
Protects unique tropical ecosystem protecting Mangrove forests.
Allows Mangroves growth to protect shore line.
Prevents debris threatening to increase ecologically sensitive areas.
Creates healthy environmental conditions through proper debris waste
disposal.
Availability of low cost construction materials that are really affordable to
economically disadvantaged families and individuals in low-income
Sustainable system to eliminate the wasteful disposal of reusable building
materials thereby having a significant impact on landfills.
DEBRIS RECYCLING PROCESS:
1. Debris collection
2. Debris bank
3. Crushing to obtain fine material

6. 4. Mixing with cement & water
5. Casting, vibrating & compacting
6. Recycled concrete products
DEBRIS COLLECTION:
Debris can be collected from
Existing debris landfills.
Removal of buildings during government projects like extending of
highways, establishment of railway lines, etc.
Demolition of buildings.
Remodeling of buildings.
Places where natural calamities (earthquakes) occur.
DEBRIS BANK:
Debris from the above areas are transported to the site of manufacture where they
are collected at a place called debris bank. The amount of area required depend on
the daily outturn that to be produced. As this process helps in producing eco-safe
environment there will not be much problem in getting loans for this project

7. CRUSHING TO OBTAIN FINE MATERIAL:
An electric-powered machine basically used in pharmaceutical and chemical
industries has been modified for the purpose. Cement and water are other inputs.
The debris is taken from debris bank and is broken down into particles, 30-40
millimeters (mm) in diameter. The particles are then powdered down by a
pulverizing machine. Some special screens enabling the machine to ground the
particles to desired levels of fineness. Coarse aggregates around 10 mm in
diameter, for example, require screens with large gaps. The dust controller sections
of the machine filter out unwanted light materials like wood particles, sundry and
other organic items.
MIXING WITH CEMENT AND WATER:
Proportioned amount of Cement and water is then added to the pulverized material
to mold it to a brick-like shape. They are mixed sufficiently as it don’t get

8. segregate or bleed. The water cement ratio should be fixed depend on the product
that to be produced.
CASTING, VIBRATING AND COMPACTING:
The prepared mixture is poured into the mold. They are sufficiently vibrated with
vibrators to compact and to remove air bubbles. Molded bricks are then cured
(hardened by repeated wetting and drying) for 14 days and then sun-dried.
RECYCLED CONCRETE PRODUCTS:
“Over a period, all waste material loses its ability to bind. But adding cement
reinforces the debris's binding qualities and it can be reused to make
other products” (Shashank Ninave, principal of L S Raheja College
of Architecture, Mumbai). The test of the products for their compliance with
Indian standards on moisture absorption, compressive strength and abrasion also
resulted with positive. Other than block manufacturing they fine material after
pulverizing the debris can also be used in lean mix, basement filling.

9. ESTIMATION OF THE PLANT:
The plant can cost around 2.5 lakhs. It can recycle a tonne of debris in a day.
Debris the main raw material are taken in free of cost . The products can be given
in discount price to those who donates debris.
COST EFFECTIVENESS:
The blocks produced from the recycling debris will fall under the category of green
building material. The Products from recycled aggregates are substantially cheaper.
100 sqft of wall construction requires about 950 bricks whereas only 112 blocks
required. Substantial saving in the material &labour.Even surfaces in block work
save substantial quantity of mortar.
BRICK AND BLOCK WORK COMPARISON:
Bricks are produced from the fresh rich Blocks are produced from the recycling
soil debris
Burning of bricks emits poisonous gases The process emits no gases
Valuable timber burnt in kiln No burning process
Excessive breakage during transportation Minimal breakage during transportation
Hacking of walls required to lay service No hacking required .The cavity allows
lines service lines to pass
Un-uniform brick sizes result in uneven Machine cut blocks gives even and true
wall surfaces surfaces
ESTIMATED COST SAVINGS BY INNOVATIVE TECHNOLOGY:
Recycled concrete Concrete products from Savings%
products natural aggregates
Solid blocks Solid blocks 25
Hollow blocks Hollow blocks 30
Paving blocks 60 mm Paving blocks 60 mm 25
thick thick
Paving block 80 mm thick Paving block 80 mm thick 30

10. BENEFICIARIES OF THE PROJECT:
INFLOW – PRODUCERS OF THE POTENTIAL WASTE:
Developers
Manufactures
Distributors
Homeowners
Remodelers
Corporations
Homebuilders
General Contractors
OUTFLOW – CONSUMERS OF THE PRODUCT:
Statewide consumers
Average people community in need of residents
Non-profit charities
Home improvement related businesses
Remodeling/Construction industry
CONCLUSION:
Thus the debris proves its characteristic of reusing inspite of damaging the society
in various aspects. Using products from debris also makes many in buying
construction materials in low cost.
“Construction waste is the responsibility of not merely the builder, developer or
debris operator, but of each and every resident in the city who is constructing,
renovating or demolishing their place."
- Bejoy Davis, the CYBC’s project manager.
REFERENCE:
1. Mr.N.N.Shirgoankar , project report of CYBC(CIDCO-YUVA
BUILDING CENTER)
2. STAR DUST demolition business plan

11. 3. Construction and demolition waste management department, Delhi
government
4. Solid waste management, Florida
Department of Environmental Protection
Solid Waste Section,
2600 Blair Stone Road,
Tallahassee, Florida 32399-2400.