An approach to Debris Management

The CIDCO-YUVA Experiment

CITY & INDUSTRIAL DEVELOPMENT CORPORATION OF MAHARASHTRA

Construction activities in Mumbai consume huge volume of bricks daily

Prime agricultural lands surrounding the city exploited

Removal of topsoil leads to severe soil erosion and devastates agricultural potential

Need - Construction solutions that do not degrade our ecosystems

Bricks of clay

Substitute for hazardous and air polluting brick making industry

Brick kilns contribute greatly to air pollution where they operate and produce relatively large emissions of the greenhouse gases

Bricks of clay

Brick kilns are typically fed with fuels such as coal/old tyres..

Construction waste, Renovation waste and demolition waste

Debris

Mumbai generates 7500 tons of solid waste/day and 30% is debris (2250 tons/day)

Increasing land prices and more construction activities are forcing the demolition of old structures and building new structures – Creation of more debris

If the external surface of a building of 20 floors is repaired, the waste generated would be ~ 200 truckloads

Renovations/ Repairs – Difficult to monitor

Only regulation - Area to be cleaned up from all wastes, after the completion of work

The Debris issue

Municipal Corp. refuse the entry of debris into dumping grounds other than required to cover the garbage

Proper disposal a concern due to lack of space in Mumbai

Carting over long distances increases transportation costs - makes the entire “business” unprofitable

Clandestine dumping in the creeks - destroying mangroves (Versova, Gorai, Charkop)

The Debris issue

Due to few viable alternatives, dumping of debris by roadsides, empty plots, watercourses, etc

Destruction of valuable mangroves, clogging of drains

Debris - Breeding ground for rodents, insects, reptiles

Over time, people start dumping organic waste on top of debris - Waste disposal problem leads to health hazard

Environmental Degradation

Impact on Navi Mumbai

Dumping of debris within NMMC jurisdiction without permission has been rampant

Debris from the construction sites in Mumbai is being dumped on Mangroves

Illegal debris dumping witnessed along the Palm Marg/ MIDC areas

NMMC constituted six anti-debris mobile squads

25 trucks confiscated (Dec.’10)

Electric junction box in Sector 12, Bonkode surrounded by construction debris

Use of waste that would otherwise be dumped and reduces the demand for environmentally unsound building materials

Debris Recycling

CIDCO – YUVA Experiment

The Youth for Unity and Voluntary Action (YUVA) is a non-profit NGO that works to protect the fundamental human rights of all people, particularly the marginalized

YUVA in collaboration with CIDCO has set-up a CIDCO – YUVA Building Centre (CYBC) in 1999

CYBC developed a innovative debris recycling technology and brought it to the ground by way of a demonstration plant

CIDCO has provided a 3,500 sq metre plot for the plant at a nominal lease amount

Location

The Debris Recycling Process

Debris sourced from construction sites is broken down into particles, 30-40 millimeters (mm) in diameter

Particles are then powdered down by a pulverizing machine

Special screens enable the machine to grind the particles to desired levels of fineness

Dust controller sections of machine filter out unwanted materials viz. wood particles/sundry other organic items Cement and water is then added to the pulverized material to mould it to a brick-like shape Moulded bricks are then cured (hardened by repeated wetting and drying) for 14 days and then sun-dried

The Process

Application

Walls

Application

Pathways

Gardens

Recycled debris sand is well suited to use as sub-base for street pavers

Plant Basics

The CYBC can recycle 3 tonnes debris/day A recycled concrete block costs Rs 21 as against Rs 28

for a block made from fresh material Recycled blocks show above average strength It can produce 1,200 hollow concrete blocks or 2000

pavers of various designs and shapes

The Recycled Block Advantage

BRICKS BLOCK

Produced from fresh rich soil Produced from recycled debris

Burning of bricks emits toxic gases

The process emits no gases

Valuable timber/saw dust/paddy husk is burnt in kilns

No burning process

Breakages during transportation Minimal breakage

Breaking of walls to lay service lines

Cavity for service lines to pass

Un-uniform brick sizes results in uneven wall surfaces

Machine-cut gives even and true surfaces

Channelized disposal of C & D waste Reduced disposal to landfill sites and other sites Lesser Sand and Top-Soil excavation Application of Hollow Blocks cheaper than clay bricks Cost of Raw Material is lesser than fresh Sand and

Aggregates

The Clay Brick and Debris issue

Benefits

Two community centers in Rapar, Gujarat, one such centre in Mumbai have already used the recycled debris

Construction industry remains unconvinced about recycling technology

Builders insist for CBRI/ Govt. Agency certification

CYBC experience tells that debris delivery is not very efficient Dumping of debris from Mumbai in Navi Mumbai can be channelised to ensure continuous availability of feedstock

Observations

Experiment has potential to cater to location wise requirements

Mechanism to ensure off-take on regular basis by builders/govt. agencies

For the project to be commercially successful there is need to scale-up, test technology in the market, create more awareness and demonstrate its utility on a regular basis

MCGM had extended a call to the international engineering community to design, construct and manage a 500-ton per day construction and demolition (C&D) waste recycling facility for the city. Results awaited

Observations

Thank You