Page 3 - Circular Economy - Andrew J. Minson

point of view

Secondly and more briefly, building design strategy. Two will initially be focussed on ensuring procedures are in place
competing approaches to building design in response to circular to process returned concrete and to encourage maximum
economy are demountable structures or long-life loose-fit recovery of this returned concrete thereby minimising waste
structures. The first is self-explanatory. The second is about to disposal. The data collection of use in concrete of recycled
both engineering the structure for longevity and designing for aggregates and recycled concrete aggregates has not been
architectural flexibility (loose-fit) so that future modifications, a priority because of the reasons given above. The use of
refurbishments and even re-purposing can be done with secondary cementitious at the ready-mixed plant is another
minimum of work to ensure the asset does not become circular economy opportunity, but once again is a lower priority
obsolete. The first maximises closed loop; the latter slows the for data collection, because it is not fully in the control of the
loop. Which is most appropriate depends on a project. Both ready-mixed concrete producer: addition can be at the cement
require some anticipation of what the future holds, and it is this plant and overall replacement level is contingent on client
anticipation, or assumption about the future, that makes a whole specification.
life cycle assessment comparison between the options difficult
and perhaps even subjective. I would contend that housing, GCCA has become a member and is a keen supporter of the
education and medical facilities are typically known needs Concrete Sustainability Council (CSC) - a not for profit that
that will last for many decades and into the next century and a administers the only global responsible sourcing scheme for
long-life loose-fit will enable most efficient use of resources. As concrete. Given that society is demanding material supply in
a structural engineer I can design this more resource efficiently excess of that available from recycling, responsible sourcing of
than a demountable structure. But for a project which is only those virgin materials needs to be in place. CSC has a supplier
needed for a short period, a less structurally efficient design may certification scheme that covers virgin aggregates. In July
be the answer in order that whole elements – columns, beams 2019 CSC added a route for supplier certification for recycled
and floor units - can be dismantled, transported and erected aggregates (Concrete Sustainability Council-2019).
elsewhere. All the impacts must be considered on a project by
project basis to determine the optimum solution. In terms of our global communications and advocacy, GCCA
communicates the sustainable credentials of concrete and why it
4. gcca cIrcular EconoMy actIvIty should be the material of choice. When appropriate we use the
lens of circular economy to do this. We communicate what our
The GCCA has a spectrum of activity that can be described industry is doing in terms of circularity in production and how
under the umbrella of circular economy: relating to both concrete can be designed and used to contribute to a circular
production and how concrete is used. GCCA has been passed economy. For example, I did this at the World Built Environment
responsibility for the global annual data collection for the Forum in New York in May 2019.
cement industry previously administered by the Cement
Sustainability Initiative under the World Business Council for
Sustainable Development. The GNR data (“gCCA in numbers”)
is a key tool in how key sustainability progress is monitored and
reported. With respect to circular economy, key data reported is
clinker to cement ratio (i.e use of secondary cementitious) and
the use of biomass and alternative fuels, such as municipal and
industrial refuse. These refuse materials have been diverted from
landfill and incineration and are co-processed during cement
manufacturing. Use of biomass and alternative fuels reduces
consumption of fossil fuels and has seen an eight-fold increase
between 1990 and 2017 (GCCA-2019).
Andrew Minson presenting at the World Built Environment Forum,
The GCCA has published guidelines to enable cement New York, May 2019.
producers to implement best practice. One of these guidelines
is on co-processing of wastes which offers higher environmental 5. our Industry MEssagE
performance than landfill and incineration. It is a practical, cost-
efficient and safe waste management option (GCCA-2019). Our industry messages in terms of circular economy can
be summarised as below with the specific circular economy
Forthcoming GCCA guidelines and data reporting initiatives outcome appended in italics.
include concrete production at ready-mixed plants where there
are several opportunities for implementing and demonstrating • Concrete is durable – (Slow resource loop).
application of circular economy thinking. Data collection • Concrete is fully recyclable – (Closed resource loop).

The IndIan ConCreTe Journal | JanuarY 2020 21