SUPPLY CHAIN
Setting green in concrete
If you are asked to name an industry sector that is known for its sustainability, the odds
are pretty high your first response is not going to be the pre-cast concrete flooring
industry. However, this is a prejudice that is not warranted. Geraldine Faulkner reports.
T
here are several reasons a major benefit, according to the technical elhag points out that precast concrete
for casting the precast flooring executive. flooring requires no packaging and because
industry in an eco friendly light, “Total energy consumption at precast flooring it is manufactured in a factory controlled
according to Dr Hafiz Elhag, factories was around 206.4mj per tonne of environment, there is reduced site waste.
technical executive of British Precast, a member net production, making it a total of 1,510mj/t “It is made to fit. Plus it offers less weight
of the industry’s trade body, the Precast Flooring compared to 25,900 to 39,000mj/t of product in per m
2
compared to insitu and other options,” he
Federation (PFF). steel mills (primary energy) and over 2,415mj/t states.
For starters, in excess of 95% of concrete of timber products for growing, harvesting and an important factor for any client,
constituents are locally sourced to the point of sawing activities and another 1,600mj/t for kiln particularly those who have worked in buildings
production. added to which, precast production drying.” with squeaky timber floors, is sound insulation.
facilities are located throughout the UK resulting It is also possible to incorporate recycled “Precast concrete flooring has sound
in the majority of materials being transported content into concrete along with products such insulation exceeding 45dB,” adds elhag before
no more than 60km and research has found that as slurry and pulverised fuel ash (PFa); a by- producing an industry trump card. “It has
the combined impact of sourcing (including product of a coal-fired power station. inherent fire resistance with up to four hours
reinforcement steel) is between 1.78 to 6.29kg of One of the most cited criticisms of any designed fire resistance and fires in structures
equivalent CO2 per one tonne of net production. manufacturing industry is the factory-to-site indicate actual resistance performance better than
a big plus in the manufacture of precast transport emissions. designed.”
concrete flooring is its factory controlled The technical executive dismisses this in the What about thermal mass potential?
environment. case of the precast flooring sector. “It can take considerable heat in the summer
“This leads to reduced factory waste and “an articulated lorry can transport up to 28 and a longer time to transfer heat from outside
energy consumption,” explains elhag before tonnes of product in one trip,” he says. “The to inside. added to which, it stores more heat in
adding that: “an eight week survey at a number fuel consumption is low; generally below 0.6mj winter and can emit it back to the inner building
of PFF member factories found that waste levels per km per tonne. also, there are reduced CO2 when the room temperature drops,” responds the
did not exceed 2% for most jobs evaluated.” emissions - less than 0.05kg of CO2 per tonne.” technical executive.
a reduction in energy consumption is also Nor does it end there. It is well known that concrete has a long shelf
Hanson's two-way flat slab technology includes recycled 'void formers', i.e. plastic balls, to create lighter concrete slabs.
34 SuStaInable SolutIonS December/January 2009
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