The concrete industry, as well as recycling
its own process waste, is very active in the use of by-products,
secondary materials and material diverted from the waste stream to
reduce its demands on primary raw materials.
Replacement of fossil fuels
Material diverted from the waste stream for use as a
fuel source, as a percentage of total energy use
The concrete industry indicator shows the proportion of energy
derived from materials diverted from the waste stream as a
percentage of total energy use.
The value of 30.2% for 2012 has exceeded the target of 21%. The
2020 target has been set at 50% requiring a significant improvement
from the 2008 baseline value of 17.3%.
Additional cementitious materials
The amount of additional cementitious materials as a
proportion of total cementitious materials
The indicator reports the percentage of additional cementitious
material as a percentage of the total cementitious materials.
The values for this indicator are consistently around 30% but the
2012 target of 33% was not reached. As the level of additional
cementitious is related to the mix of concrete being produced this
indicator is affected by the types of project in the marketplace.
The target has been extended to 35% for 2020.
The use of recycled/secondary
aggregates as a proportion of total aggregates used
Depending on the application and the type of concrete there is
often an opportunity to incorporate recycled aggregates previously
used in other projects and secondary aggregates that may be
by-products from other processes e.g. ‘stent’ from china clay
production and granulated slag from steel making.
Environmentally it is preferable to use these materials as close as
possible to their origin, although their embodied CO2 value can
exceed virgin materials. This decision should be made on a project
basis to ascertain benefit. For this reason the concrete strategy
does not include a numerical target for the proportion of
recycled/secondary aggregates of the total aggregates used but
reports on the trend. This has been consistent at around 5% by mass
in concrete production, although some products can have
significantly higher levels.
Recycled steel reinforcement
Steel reinforcement manufacturing BAR members used around 94% of
recycled ferrous metal waste as a proportion of the raw materials
consumed in their electric arc furnaces (EAF). While reinforcement
fabricators used 100% EAF material in producing and supplying rebar
for use in concrete.
Please read Our Strategy 2020 Commitments
information on the materials efficiency indicator can be found
in the full report.