The secret of the sand castle helps restore ancient construction techniques

The secret of a successful sand castle can assist in restoring an environmentally friendly construction technique, according to a new study by Durham University.

Researchers at the Applied School of Durham University, conducted a study of the strength of clay, an increasingly popular material and considered a sustainable construction method.

Like a sand castle that needs water in its composition to stand firm, Durham University engineers have discovered that clay's strength depends heavily on its water content.

Clay is a material made of sand, gravel and clay that is moistened and molded into blocks to build walls. Sometimes stabilizers such as cement are used more, but in this study scientists are only interested in materials that do not stabilize.

The study was funded by the Physical and Applied Science Research Council (EPSRC) and published in Geotechnique. The research results show that part of the power this material has is due to the presence of a small amount of water inside it.

Cylindrical samples have undergone a three-cylinder test, in which external pressures have been applied to test the support of this type of wall. Researchers have found that the attraction between soil molecules in the presence of a small amount of water is the source of this material's strength.

Scientists say clay walls are left to dry after construction, in suitable climatic conditions, can dry out but not lose water. The remaining small amount of water provides a significant strength for the wall over time.

Scientists say their work is suggestive of the future of building materials using clay materials, when the link between the strength of this material and its water content is made. more clarity.

People spend more and more interest in using this technique because it helps reduce dependence on cement in construction (cement production accounts for 5% of human CO2 emissions into space ( first)). At the same time, the materials to create clay can be mobilized right at the construction site, contributing to reduce transportation demand.

In parallel with the announcement of future new construction techniques, the team also hopes their findings can support the preservation of ancient clay-built buildings with consideration. Protection methods do not have too much water penetrating and weakening the construction. Paul Jaquin, a project researcher, is currently working for an application consulting firm (Ramboll, UK) on construction projects with soil materials around the world.

The research project leader Dr. Charles Augarde of Durham University Applied School said: 'We know that clay can withstand time, but so far has not understood the source of strength of the type. this land is thorough. '

'If we don't understand, we cannot effectively protect ancient clay structures, nor can we plan to build new buildings with this material economically.'

Monastery in Kagbeni, belonging to the Buddhist kingdom in Mustang, Nepal.The monastery was completed in 1429. (Photo: Paul Jaquin copyright / Durham University)

'Our initial tests show that the source of the strength of this material is related to the water content in it.'

'With more understanding of this issue, we can begin to consider the use of clay as a green material in the construction of new buildings as well as the preservation of ancient buildings that were built by technology. this technique. '

Clay has been developed in ancient Chinese society around 2000 BC , when people used this technique to build walls around settlements and it quickly spread throughout the world - extracting a The group's other new father is associated with Dr. Chris Gerrard of Durham University Archeology (*). The Great Wall of China and the Alhambra palace complex in Granada, Spain have been built with clay materials.

In the UK, this technique has been used in the construction of low-cost homes in Amesbury, Wiltshire after World War I, and it is also a recognized construction method in some parts of the United States and Australia.

The popularity of eco-friendly homes shown on television shows like Grand Designs has also generated attention in the community.

Dr. Augarde, co-founder of the Association of Soil Materials Building (EBUK), a newly formed association this year to advocate for the protection, understanding and development of buildings in the United Kingdom. England

EBUK brings together builders, researchers, academics, architects, manufacturers and many other stakeholders to work in common areas of interest at the national and regional levels.

Tom Morton, the secretary of the EBUK association, said: 'This type of research is very valuable when the construction industry is analyzing reasonable traditional measures and applying them to sustainable construction in the 21st century. '

These low-carbon technologies are most likely to be successful because of the combination of research universities, such as Durham, with the commercial knowledge of construction industry members. build, and the fact that we are seeing very exciting developments in this area. '

Refer:
PA Jaquin, CE Augarde, D. Gallipoli, DG Toll.Độ dài của unstabilised rammed earth Materials.Géotechnique, 2009;0 (0): 090505015147034 DOI: 10.1680 / geot.2007.00129