03 Jun 2009 09:06:07
Sandcastles hold secret to low carbon building
The secret behind the construction of sandcastles could help scientists to rediscover a long-lost, environmentally-friendly building technique, it has been suggested.
According to a study led by Durham University's School of Engineering, the strength of sandcastles depends on how much water is included in the mix.
The researchers found that the same holds true for rammed earth, an increasingly popular commercial building material that is manufactured from sand, gravel and clay and compacted to build walls.
It is hoped that the technique could reduce the construction industry's reliance on conventional materials such as cement, which is estimated to be responsible for five percent of manmade carbon dioxide emissions.
Writing in the journal Geotechnique, the team suggested that the addition of a small amount of water can increase the strength of rammed earth and make it a much more viable construction material.
Highlighting the significance of water to the process, Dr Charles Augarde, project leader, said: "We know that rammed earth can stand the test of time but the source of its strength has not been understood properly to date.
"Without this understanding we cannot effectively conserve old rammed earth or make economic designs for new build."
Rammed earth appears to date back more than 4,000 years, and was first used in ancient China to build walls around settlements. It was also used to build parts of the Great Wall of China.http://www.eurekalert.org/pub_releases/2009-06/du-sos0602...