ABSTRACTDebris, the construction waste is used as a substitute of fine and coarse aggregatein the manufacture of hollow blocks and pavement blocks. The debris collectedfrom site is crushed down to the size of coarse aggregate (40-50mm size andremaining 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 tocompact and then cured for 14 days and sundried. Cost of the blocks from debris isvery cheaper than bricks and helps in saving 25-30%. It also helps in reducingvarious environmental degradation promoting environmental upgradation. Oncomparing with bricks also results in positive. The ultimate goal of the project isto substitute a portion of clay brick production with recycled material collectedfrom the overwhelming amounts of C&D waste produced in the city each day.
WHAT IS DEBRIS?Debris or Construction & Demolition (C& D) is the waste obtained in pullingdown 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
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.
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
4. Mixing with cement & water 5. Casting, vibrating & compacting 6. Recycled concrete productsDEBRIS 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 theyare collected at a place called debris bank. The amount of area required depend onthe daily outturn that to be produced. As this process helps in producing eco-safeenvironment there will not be much problem in getting loans for this project
CRUSHING TO OBTAIN FINE MATERIAL:An electric-powered machine basically used in pharmaceutical and chemicalindustries 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, 30-40millimeters (mm) in diameter. The particles are then powdered down by apulverizing machine. Some special screens enabling the machine to ground theparticles to desired levels of fineness. Coarse aggregates around 10 mm indiameter, for example, require screens with large gaps. The dust controller sectionsof the machine filter out unwanted light materials like wood particles, sundry andother organic items.MIXING WITH CEMENT AND WATER:Proportioned amount of Cement and water is then added to the pulverized materialto mold it to a brick-like shape. They are mixed sufficiently as it don’t get
segregate or bleed. The water cement ratio should be fixed depend on the productthat to be produced.CASTING, VIBRATING AND COMPACTING: The prepared mixture is poured into the mold. They are sufficiently vibrated withvibrators 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 cementreinforces the debriss binding qualities and it can be reused to makeother products” (Shashank Ninave, principal of L S Raheja Collegeof Architecture, Mumbai). The test of the products for their compliance withIndian standards on moisture absorption, compressive strength and abrasion alsoresulted with positive. Other than block manufacturing they fine material afterpulverizing the debris can also be used in lean mix, basement filling.
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 givenin discount price to those who donates debris.COST EFFECTIVENESS:The blocks produced from the recycling debris will fall under the category of greenbuilding material. The Products from recycled aggregates are substantially cheaper.100 sqft of wall construction requires about 950 bricks whereas only 112 blocksrequired. Substantial saving in the material &labour.Even surfaces in block worksave substantial quantity of mortar.BRICK AND BLOCK WORK COMPARISON:Bricks are produced from the fresh rich Blocks are produced from the recyclingsoil debrisBurning of bricks emits poisonous gases The process emits no gasesValuable timber burnt in kiln No burning processExcessive breakage during transportation Minimal breakage during transportationHacking of walls required to lay service No hacking required .The cavity allowslines service lines to passUn-uniform brick sizes result in uneven Machine cut blocks gives even and truewall surfaces surfacesESTIMATED COST SAVINGS BY INNOVATIVE TECHNOLOGY:Recycled concrete Concrete products from Savings%products natural aggregatesSolid blocks Solid blocks 25Hollow blocks Hollow blocks 30Paving blocks 60 mm Paving blocks 60 mm 25thick thickPaving block 80 mm thick Paving block 80 mm thick 30
BENEFICIARIES OF THE PROJECT:INFLOW – PRODUCERS OF THE POTENTIAL WASTE: Developers Manufactures Distributors Homeowners Remodelers Corporations Homebuilders General ContractorsOUTFLOW – CONSUMERS OF THE PRODUCT: Statewide consumers Average people community in need of residents Non-profit charities Home improvement related businesses Remodeling/Construction industryCONCLUSION:Thus the debris proves its characteristic of reusing inspite of damaging the societyin various aspects. Using products from debris also makes many in buyingconstruction materials in low cost. “Construction waste is the responsibility of not merely the builder, developer ordebris 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
3. Construction and demolition waste management department, Delhi government4. Solid waste management, Florida Department of Environmental Protection Solid Waste Section, 2600 Blair Stone Road, Tallahassee, Florida 32399-2400.