CM takes a look at new and future developments in concrete, from digital design innovation to low-carbon cement production.
3D printing helps Ely bridge project
Formwork specialist RMD Kwikform helped the complicated construction of the Ely bypass bridge (main image, top) in Cambridgeshire by 3D-printing a visualisation of its planned solution (above).
The V-shaped bridge piers have a complex geometry, with heavy loads running through to the foundations, which was difficult to model accurately in 2D. RMD Kwikform’s 3D-printed model helped main contractor VolkerFitzpatrick and formwork contractor Sword visualise the project, rectify potential issues in advance, and understand the engineering tolerances.
Keltbray installs ‘first ever’ cement-free pile
Keltbray Piling has installed what it claims is the first ever permanent works pile using a zero cement concrete, Cemfree.
Working for Taylor Wimpey at Mount Pleasant, London, Keltbray is installing a secant wall and bearing piles for main contractor Bouygues.
The Cemfree material, manufactured in the UK by DB Group, is a low-carbon alternative to traditional cement, which Keltbray says has the structural characteristics of traditional concrete, is more resistant to chloride ingress and requires fewer construction joints and less crack-control steel.
Old clothes and carpets fuel cement plants
Cement manufacturing is energy-intensive, and Cemex has been pushing the use of alternative fuels, which now account for 58% of its UK production.
Climafuel uses household waste, including shredded paper, carpet, textiles and plastics. Cemex is also replacing cement through use of fly ash and GGBS in mixes, while byproducts of the production process – cement kiln dust and bypass dust – are being developed for use as replacements for cement in soil stabilisation applications.
Cemex is also using 100% renewable electricity at all its supplied sites.
Hanson’s record pour on tallest City tower
Hanson says it recently delivered the highest ever lightweight concrete pour in London, on 22 Bishopsgate, the 278m tower which will be the tallest building in the City on completion next year.
The materials firm is supplying 52,000 cu m of structural concrete on the 62-floor steel-framed tower, which has a central jump-form concrete core and perimeter columns.
Hanson, which recently reached level 54, says its pour beats the previous record of 50 floors set by RMC at One Canada Square, Canary Wharf, in 1984. Main contractor is Multiplex while Careys is concrete contractor.
Cambridge researchers developing self-healing concrete
Cambridge is the latest university to research the potential of “self-healing” concrete, using microencapsulation technologies developed by Dolomite Microfluidics.
Microcapsules containing “healing” agents – such as epoxy or polyurethane – are added to the material to allow self-repair of small cracks which develop due to fatigue.
Cambridge’s researchers plan to add the microcapsules to the concrete prior to use, which are ruptured as cracks appear, releasing their payload and stabilising the material.