Waste reduction final report -4 - Test Input

components. However, recycling of steel means the steel goes back to the mill to be melted
down for production of new steel which generally requires more energy. Similarly, concrete
frame buildings can be entirely reused saving on the production of new concrete, or the
concrete can be crushed and down-cycled, but this usually only displaces some of the primary
aggregate and not the concrete (which includes cement). Reuse will generally lead to
considerably more significant greenhouse gas reductions, as can be seen in Table 8.
This study summarised that the overall recycling and reuse initiatives saved 1,073,563 kg of
carbon dioxide equivalent (CO 2 e), or 4.8 kg of CO 2 e per tonne of diverted CRD waste. The
material contribution to net greenhouse gas savings was as follows: concrete (69%), vinyl
windows (13%), steel (12%), asphalt (4%), with all the remaining materials amounting to
2%. The concrete was very significant due to three sites reporting concrete reuse which was
attributed to the reuse of a building. Due to the greater benefit of reuse, this strategy
accounted for 85% of the greenhouse gas savings across the seven sites assessed.
Table 8: Greenhouse Gas Savings by Site and Material Type 18
Case
study
#
Material
Quantity
(tonnes)
Diversion
method
Substitutes for
or avoids
GHG/
unit
(kg)
1 gyproc 7.47 recycled raw gypsum 24 179
5 gyproc 2.11 recycled raw gypsum 24 51
7
Net GHG
savings
(kg)
steel stall 1.36 reused hot-rolled sheet 1,862 2,532
asphalt 16.36 reused asphalt 111 1,816
clay brick 51.14 reused clay brick 2.48 7,440
concrete 3005 reused concrete 170 295,800
9 vinyl windows 3.11 reused vinyl windows 122 139,080
11 concrete 8,965 recycled aggregate 3.44 26,357
structural steel 54.82 recycled virgin steel 820 44,952
rebar 97 recycled virgin steel 820 79,540
copper 6.1 recycled virgin copper 1600 9,760
wood 257.52 recycled Animal bedding 11 2,833
13 concrete 4600 reused concrete 170 415,820
asphalt 385.5 reused asphalt 111 42,791
14 wood 4 reused wood 68 272
steel cladding 2 reused galv. steel 1,965 3,930
concrete 2.1 reused concrete 195 410
Total 1,073,563
18 Let’s Climb Another Molehill - An Examination of Construction, Demolition and Renovation (CRD) Waste
Diversion in Canada and Associated Greenhouse Gas Emission Impacts, The Recycling Council of Ontario
(RCO), 2005, Chapter 4.
21