Leiths Newsletter Issue 22 - Magazine - Page 5
Leiths News : QUARRIES DIVISION
The integration of our CemLime into the ready-mix business is ongoing and this is now available in
Aberdeen, Highlands, and the West of Scotland. Over the coming months, Leiths will be looking to
increase the use of CemLime as more opportunities for lower carbon cements materialise through
speci昀椀cation and customer demand. Leiths continue to work closely with our cement suppliers and
undertake the necessary conformity testing of limestone 昀椀nes to BS 8500-2: Annex B so that we have
monthly test data.
Since CemLime was introduced to the business, we have achieved signi昀椀cant C02 reductions. Our
Rigaflow self-compacting concrete can offer C02 reductions of 98kgs per m³ (23%) compared to the same
mix with CEM I. Our CemLime blocks manufactured at Midlairgs now has up to 20% CemLime generating
substantial carbon savings with an average home built with CemLime blocks reducing the C02 by 382 kg.
Through the use of CemLime and Leiths continued commitment to providing lower carbon solutions,
Leiths are making the Grey Greener to achieving a brighter cleaner future.
page 4
Building an average
home using CemLime
blocks reduces C02
output by 382kg!
That’s the equivalent
of turning off 23,000
light bulbs for
an hour!
Recycled Concrete Aggregate - Making the Grey Greener
The amount of construction aggregates from
recycled and secondary sources in the UK has
reached an all-time high as producers invest in
ways to turn ‘waste’ into materials that can
be used in concrete production.
A recent report from the Mineral
Products Association (MPA) shows that
the total volume of recycled and
secondary materials reached a record
73.5 million tonnes in 2022.
Under BS 8500, the complementary British
Standard to BS EN 206, recycled
aggregates within concrete are split
into two categories; crushed concrete
aggregate (CCA) and recycled aggregate
(RA). RA is produced from crushing inert
construction and demolition waste. CCA
consists primarily of crushed concrete.
Joss have been supplying recycled sand
and aggregates from our Lochhills
Quarry for many years. Production
trials have recently been carried out on
producing CCA that can then be used in
concrete production.
CCA Crushed Concrete Aggregate
When using recycled aggregates within
concrete, the constituents need to be
assessed to ensure that its inclusion
does not affect the water demand and
cement content, as this is the biggest
contributor to the embodied carbon of
concrete.
BS 8500, the British Standard for
concrete, permits the use of recycled
concrete aggregate (RCA) in concrete
production. Speci昀椀cally, it allows up to
20% of the natural coarse aggregate to
be replaced by crushed concrete
aggregate (CCA) in Designated
Concretes RC20/25 to RC40/50,
without requiring a declaration. Higher
percentages are also possible and 100%
is permitted in GEN 0 to GEN 3 concrete
(non-reinforced concrete for footings
and floor slabs in domestic
applications).
Leiths are continually striving to provide
lower carbon, sustainable solutions to
our customers. With the inclusion of a
CCA in the ready-mix, this helps promote
circularity and enables Leiths to make
the “Grey Greener”.
Stripping Works at Dalwhinnie Quarry
2025 started with a number of projects across the company, one being the
development of Dalwhinnie Quarry.
The management team was tasked to enlarge the operational footprint of the quarry and
create screening bunds around the perimeter of the site. This work required a specialist earth
moving contractor which was ideal work for MacDonald Groundworks Ltd (MGL) to
undertake.
The 昀椀rst phase of activity was the Bund Construction Management Plan. Utilising two of their
Volvo EC250 excavators and two new Volvo A30G dumptrucks MGL commenced the works
with stripping and stockpiling peat, constructing roads and forming the screening bunds.
The stockpiled peat was then spread across the bunds to enhance natural growth which will
reduce the visibility of the site from both the A9 and the A889 Laggan Road.
The next phase was to strip an area of the quarry which would be ready for future blasting.
Time was of the essence as all works needed to be completed before the nesting birds
breeding season which is typically between April and August.
The team worked tirelessly leaving 15,000m² of stripped rock head ready for blasting and
a total of 700m of 昀椀nished screening bunds around the perimeter of the site all before the
April deadline. Great teamwork by all which has now left Dalwhinnie Quarry ready for rock
extraction.
