Ingenieur Vol.82 April-June2020 | Page 46

INGENIEUR Table 3: Comparison of reduce, reused, recycle and recover Reduce Reused Recycle Recover ● Where possible stop waste coming on-site in the first place. ● This can be achieved by ordering only quantities which are required and communicating to manufacturers to order size-specific items which do not require cutting to size. ● The next option should always be to consider whether the materials can be reused, either on-site or by someone else. ● Items such as timber, tiles and bricks are often easily re-used. Packaging items such as pallets and crates may also be collected by the supplier for re-use elsewhere. ● This option is for all materials which cannot be reduced or reused. ● It involves processing the waste material, for example, crushing concrete to transform into aggregate or melting metal or glass to form new products. ● Some recycling can be carried out on-site, but often the waste must be sent to an off-site recycling company for processing. ● Segregation of wastes to prevent contamination is important for recycling to ensure that skips are not rejected by the waste contractor. ● Most construction materials can be recovered with the right recycling equipment, such as trash compactors, shredders, crushers and balers. ● Commonly recovered materials from construction projects include: ● Wood, brick and concrete ● Gypsum wallboard ● Steel (which is 100% recyclable), and other metals ● Asphalt paving and shingles ● Non-asphalt roofing and shingles ● Architectural salvage materials ● Material recovered from land clearing Figure 4: Systematic approach towards construction waste management through a building life cycle 44 VOL 82 APRIL-JUNE 2020