Rammed Earth Construction
One of the most important factors in sustainable design, particularly in building, is the transportation of raw materials. Transportation in the industry accounts for a huge amount of energy, infrastructure and time spent.
Increasingly, architects are taking to using locally sourced bulk materials, villa welpelo, such as timber from near-by forests. This is a good step, but there is often an over-looked material lying around in plentiful quantities at building sites.
This is where rammed earth comes into view. This ancient technique is coming into focus more and more as news of the relative simplicity and low-cost of building with earth become more widely known.
In short, a strong temporary formwork is constructed in the shape of the desired wall. Moist earth is applied in layers into this mould and stamped down with force. These days, pneumatic rammers are often used. As layers of moist earth are added, compacted into shape and dried, the wall takes shape.
The result is a thick wall that is surprisingly strong. Examples are found all over the world, and increasingly in western architecture. A UK lecture theatre by Pat Borer and David Lea Architects has load-bearing, circular walls over 7m high.
Similarly, a Mexican school of Visual Arts by Taller de Arquitectura-Mauricio Rocha displays the layers of rammed earth to maximum effect. The solid walls are elegant proof of the principles used. The colour variations give the wall an appealing character.
Reinforcing the earth with steel gives the construction much more strength. Traditional structures along the Pacific rim use local materials, such as bamboo or twigs, for added strength and to withstand earthquakes.
A more modern additive is a low percentage of cement, which binds the material together far more strongly. Even with this addition, using rammed earth constructions is a fantastically low-carbon approach to building. The thick walls also retain more heat than brick-and-mortar construction, which has led to an A+ rating given to rammed earth by the BREAAM institute