Construction and Demolition (C&D) materials consist of the debris generated during the construction, renovation and demolition of buildings, roads, and bridges. C&D materials are generated when new building and civil-engineering structures are built and when existing buildings and civil-engineering structures are renovated or demolished (including deconstruction activities). Civil-engineering structures include public works projects, such as streets and highways, bridges, utility plants, piers, and dams.
a. The composition of C & D waste can vary depending on age of building being demolished / renovated or the type of buildings being constructed. As mentioned earlier, C & D waste generation figures for any region varies as it depends largely on the type and nature of construction / demolition project activities which may be regional / site / project specific.
Under Rule 4 sub-rule (3) of CPCB, the segregation by bulk C & D waste generators shall be done into four streams such as:
iii. Steel, wood and plastics
iv. Bricks & mortar
b. Demolition waste characteristics: In India, when old buildings are demolished the major demolition waste is soil, sand and gravel accounting for bricks (26%) & masonry (32%), Concretes (28%), metal (6%), wood (3%) others (5%). Bricks, tiles, woods and iron metal are sold for reuse / recycling (BMTPC). c. Excavations, concrete, masonry and wood together constitute over 90% of all C & D waste. d. The typical composition of Indian C & D waste: The major constituents are concrete, soil, bricks, wood, asphalt and metal. Brick & masonary, soil, sand & gravel account for over 60% of total waste.
The new Bahugunatech C&D recycling plant consists of the following systems:
1.Hopper with Vibrating Feeder
2.Log Washer for cleaning
3.Trash Screen for removal of light weights
4.Sizing Screen for washed Aggregate
5.Dual Pass Hydro-cyclone system for Sand washing
C&D Waste majorly consists of:
- Cement concrete, Bricks, Cement Plaster
- Steel (from RCC, door/window frames, roofing support, railings of staircase etc.)
- Rubble, Stone (marble, granite, sand stone)
- Wood (especially demolition of old buildings)