Concrete Becomes Greener
< Back Monday, 7 February 2011Aiming to be the first 5-star green design educational building in New Zealand, the new $30 million student services building at Waikato University has seen the 'greenness' of the construction process aided by expertise from Fletcher Construction, the main contractor for the project, and Firth who is supplying the concrete. The site features a new 'green' concrete mix, GreenCrete®, incorporating recycled aggregate and fly ash from Huntly Power Station, replacing 20% of the cement content.
"When discussions were first held regarding the Green Star rating of this project we wanted to try to obtain at least a portion of the three points awarded toward the overall rating of the building for the concrete," said Tony Brown, Project Manager for Fletcher Construction. "This was virtually unheard of in the industry so we decided to talk to Firth to see what they could come up with in a mix design in the hope of maybe picking up one of the rating points. Alison Durning and Paul Donohue went away to work on a solution. The mix design Firth came up with has meant we have gained two of the possible three rating points, which has been ground breaking for the industry."
With construction well over the halfway point the foyer and an
impressive 11+m waterfall feature, which was constructed in
sections from self-compacting concrete, has been installed and is
now operational. Alison Durning, Waikato Sales Manager for Firth
explains, "the water feature divides the existing building from the
new extension. Self-compacting concrete was used with Ueriti pebble
to achieve the illusion of 'tear drops falling from the sky'. The
walls have been sand blasted and sealed, which has made the
textured areas very smooth. It's a double first for us using Ueriti
and exposing the aggregate in self-compacting concrete. To date we
have supplied approximately 900+m3 of GreenCrete® to Fletcher
Construction."
What is Green Star?
Green Star New Zealand is the country's first comprehensive
environmental rating system for buildings and was created to:
• Establish a common language and standard of
measurement for green buildings
• Promote integrated, whole-building
design
• Raise awareness of green building
benefits
• Recognise environmental leadership
• Reduce the environmental impact of
development
For more information on the Green Star rating system go to the
Green Building Council website www.nzgbc.org.nz
"We have a very good working relationship with Alison and the guys at Firth and have worked through things together," adds Tony. "We have a very good finished product at a very a high standard."
Energy saving features of the new building include a large photo
voltaic panel on the roof, a wind turbine (also roof-mounted),
regenerative drive motors on the lifts and rainwater harvesting.
Carpet, ceiling tiles and furniture will also be made from recycled
materials.
"For a product to be labelled as a Green Star
product, strict requirements and standards have to be met," says
Alison, "An extensive process has taken place with assessment
of the aggregate, mix design and our procedures. Test pad samples
were also poured at the Te Rapa yard to evaluate the
characteristics of the concrete. Testing was closely supervised to
analyse any possible alterations we would be required to make to
our formula. We have named this new mix design GreenCrete®."
Tony says that the whole process has been a learning
experience for Firth and Fletcher Construction.