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AN APPROACH TO DEBRIS MANAGEMENT

An Approach to Debris Management

 
 

Mr. M. D. Lele1, Ms. Tanvi Katre2 , Mr. Ashish Pandey3

 Chief Architect and Planner CIDCO, Architect -M.Plan (Student)2, M. tech (Student)3

m.d.lele@vsnl.net 1, tanvik1992@gmail.com2, ashkazem481@gmail.com3

094230812121 , 95522155172 , 89534197203

 
 

Abstract— The Conventional building construction activity in India has been dominated by use of bricks for over centuries. For making bricks prime agricultural land is used to a great extent. Removal of topsoil leads to severe soil erosion and devastates agricultural potential – particularly in the periphery of towns and cities witnessing accentuated urbanization.  In order to mitigate the problem of pollution arising out of proliferation of brick kilns and health hazards as its fall out, attempts are made to experiment and use non-conventional building blocks such as concrete blocks, fly ash bricks, etc.  The CIDCO-YUVA Experiment tried out in Navi Mumbai and chronicled in this Paper presents an opportunity to solve a multitude of problems faced in cities – such as shortage of building blocks by providing a substitute construction material for bricks that is excellent in quality, strength and appearance, mitigating environmental hazards, providing employment to skilled workers and last but not the least – addressing the issues raised by wanton dumping of construction and demolition waste across the towns and cities. The debris management challenge that will grow in size (as cities become older leading to accelerated pace of redevelopment of dilapidated, aged structures) is proposed to be overcome by recycling the waste to produce a variety of finished goods finding applications in our built environment such as paver blocks, concrete blocks, tiles, etc. by processing in a plant.

Setting up a strong institutional mechanism to address issues of backward and forward integration will be the key to successful implementation of such green solutions.

 

I.     INTRODUCTION

  Extent of growth in construction activities, has lead to a significant increase in construction and demolition waste in India, thus has its adverse impacts on the environment as well as health of human beings.

To minimize the impacts of demolition of construction waste and to avoid issues of pollution arising due to proliferation of brick kilns, CIDCO and YUVA (Youth for Unity and Voluntary Action ) have taken up a cost-effective and sustainable initiative. It entails the recycling of construction debris into useful bricks, paving blocks, etc. This paper explains this unique initiative regarding recycling of construction waste and its success along with its present scenario in Mumbai.

II.     Background

A.     Scenario of construction activities in Mumbai

Construction activities in Mumbai consume huge volume of bricks daily & prime agricultural lands surrounding the city are getting exploited also , Removal of topsoil leads to severe soil erosion and devastates the agricultural potential.

Also, in brick making process, brick kilns are typically fed with fuels such as coal etc. and also contribute greatly to air

pollution where they operate and produce relatively large emissions of greenhouse gases.

Therefore, there is a strong need for economical as well as ecofriendly construction solutions that do not degrade our ecosystem and Hence substitute for this hazardous and air

polluting brick industry need to be developed.

B.     The construction and demolition debris issue. 

Mumbai generates approx. 9000 tons of solid waste / day and out of which, 30% is construction, renovation and demolition debris and it is the waste disposal of the magnitude of 2700 tons/day which is difficult to monitor.

Increasing land prices and more construction activities are forcing the demolition of old structures and building new structures leads to the creation of more debris. For ex. If the external surface of a building of 20 floors is repaired, the waste generated would be around 200 truckloads.

And, municipal corporation refuse the entry of debris into dumping grounds other than required to cover the garbage.

Also, proper disposal is a concern due to lack of space in Mumbai, Hence carting over long distances increases the transport cost making the entire operation inefficient and costly affair.

In Mumbai and the surrounding region, due to policies favouring redevelopment of slums with higher FSI regime, redevelopment of old and dilapidated buildings with lucrative development potential dispensations, road widening, construction of flyovers, metro, monorail corridors, rejuvenation of downtown areas through large scale change of land uses, the building construction industry is facing a mammoth demolition activity. It is aggravating the issue of generation of construction debris by the day leading to abuse of land and environment in general. 

III.     Impacts of Construction debris

A.     Environmental Degradation

Due to a few viable alternatives, dumping of debris is done extensively on roadsides, empty plots, watercourses causing damage to environment.

Dumping in the creeks leads to destruction of mangroves for ex. Versova, Gorai, Charkop etc. Also, dumping of construction debris has its environmental impacts such as , Clogging of drains, Increase in rodents, insects, reptiles on them which have its adverse impacts on human health as well.

B.     Impacts on Navi Mumbai

Dumping of debris within NMMC jurisdiction and areas in the southern part of Navi Mumbai managed by CIDCO, without permissions has been rampant. Hence, debris from the construction sites is finding its way to Mangroves. Illegal debris dumping has been witnessed in many areas including Palm Beach Road and MIDC area. For this, NMMC has constituted six anti-debris mobile squads, and 25 trucks are confiscated.

IV.     Debris Recycling ...An alternative ?

Over viewing the adverse impacts of debris formed due to construction, renovation, demolition waste, it is necessary to find an innovative alternative for the use of debris which is economical , as well as ecological also, as use of waste that would otherwise be dumped and reduces the demand for environmentally unsound building materials.

V.     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 an innovative debris recycling technology and brought it to the ground by way of a demonstration plant.

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

A.     Location

 

   B. 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.

 

                    

                                         Figure 1 : Recycling Process

   C. Plant Basics

 

         Recycling Plant

 

The CYBC can recycle 3 tonnes debris/day and a recycled concrete block costs Rs 21 as against Rs 28 for a block made from fresh material. Recycled blocks show above average strength.

Also, it can produce 1,200 hollow concrete blocks or 2000 pavers of various designs and shapes.  

   D. Application

Bricks made out of debris can also be used to construct walls; whereas, recycled debris sand is well suited to use as sub-base for street pavers as shown in figures.

  

         Walls                       Paving Blocks                       

VI.     Advantages & observations

A.     Recycled Block Advantages:

 

BRICKS

BLOCKS

Produced from fresh rich soils.

Produced from recycled debris.

Burning of bricks emits toxic gases.

The process emits no gases: hence no pollution.

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

No burning process.

Breakage during transportation.

Minimal breakage.

Breaking of walls to lay service lines.

Cavity for service lines to pass.

Un-uniform brick sizes results in un-even wall sizes.

Machine-cut gives even and true surfaces.

 

Benefits:

- 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.

   B. Present Observations & Issues:

Two community centers in Rapar, Gujarat, -One such centre in Mumbai have already used this recycled debris.

But, construction industry still remains unconvinced about recycling technology; and builders insist for CBRI/ Govt. Agency certification.

Also, CYBC experience tells that the debris delivery is not very efficient and dumping of debris from Mumbai in Navi Mumbai can be channelized to ensure continuous availability of feedstock.

This experiment has potential to cater to location wise requirements . It also has mechanism to ensure off-take on regular basis by builder/govt agencies.  

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

Though, 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, the response is awaited.

VII.     Construction  and  demolition  waste  rules ,2016

To make existing Municipal Solid Waste Rules, 2000 more effective and to improve the collection, segregation, recycling, treatment and disposal of solid waste in an environmentally sound manner, the Central Government issued a notification related to management of Construction and Demolition wastes on 29th March, 2016.

Summary of these rules is as follows:

The rule clearly divides the duties of waste generators, Service provider, Local Authority, SPCB etc.

Duties of the waste generator include,

  1. Collection, segregation and storage of C&D waste generated, as directed by local authority.
  2. No inter mixing of C&D waste with other waste.
  3. If waste > 20 MT/day or 300MT/project/month is generated , then  segregation is to be done in 4  streams, i.e. (a) Concrete, Soil, Steel, Wood; (b) Plastics; (c) Bricks; (d) Mortar
  4. Submission of waste management plan to get approvals from the local authority before starting the work.
  5. C&D waste to be kept within the premises or get the waste deposited at collection centre /authorized processing plant.

Whereas, duties of the local authority include,

  1. Detailed directions for proper management of C&D waste within its jurisdiction and the local authority shall seek detailed plan and chalk out stages, methodology for overall activity.
  2. Seek assistance in case C&D waste is contaminated with industrial hazardous/toxic/nuclear waste.
  3. Place appropriate containers for collection and regular disposal of waste.
  4. Provide incentives for salvaging, processing and / or recycling and for use of material made out of C&D waste.

The rules clearly mention various criteria for site selection for storage/ processing /recycling facilities for C&D waste.

I.     Conclusion

Although the recycling plant witnessed initial success , it is not in use for a few years due to indifferent attitude of all stakeholders such as local authorities, planning bodies, end users , etc. and implementation issues. More particularly, it was observed that a weak institutional mechanism could not ensure a sound backward and forward integration.

The C&D waste rules, 2016 have reiterated the importance of authorised processing and recycling plants for the scientific disposal of construction and demolition waste.

Economical and ecological initiatives like this one taken by  CYBC can strengthen the institutional mechanism for efficient debris management and can be a step towards sustainable development.

 Such a mandate will force the local authorities, development agencies to ensure proper disposal of the waste and its treatment for beneficial use. This innovative concept / experiment will set an example towards a responsive and responsible city governance. It is hoped that, these authorities will take a cue and discharge their liabilities earnestly. 

                                         

 

    REFERENCES

 

  1. Information provided by CYBC, Kharghar.
  2. Presentation made by the main author at Navi Mumbai Builders' Associations Forum in 2014.

 

 

 

 

 

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