27-02-2013, 04:41 PM
GREEN BUILDING BY SUPERADOBE TECHNOLOGY
GREEN BUILDING BY SUPERADOBE.docx (Size: 2.19 MB / Downloads: 312)
ABSTRACT
Superadobe is a patented system at the service of humanity. Superadobe buildings use the structural principles of single and double curvature compression shells that have made arches, domes and also rectangular shapes. Individuals are enabled to build their own homes without the use of heavy equipment, with materials native to the country of use. Flood control, erosion control, stabilization of waters’ edges, hillside slopes and embankments, landscapes and infrastructures are applications in which superadobe system has shown great potential.
INTRODUCTION
Approximately one third of the people of the world live in houses built with earth, and tens of thousands of towns and villages have been raised practically from the ground they are standing on. Today, world consciousness about the use of natural resources and the new perception of building codes as the steward not only of individual’s safety, but of the planet’s equilibrium, are leading us into the new millennium of sustainable living.
A Superadobe structure is made by filling long or short sandbags with earth from the building site and stacking or coiling them in to layers with barbed wares in between to serve as mortar and reinforcement. Bags and wire alone are adequate for short term use, such as in disaster relief; for a permanent home, cement or lime is added to the earth, the walls are coated with plaster, and the exterior gets a waterproof coating. Many Superadobe buildings use the structural principles of single and double curvature compression shells that have made arches and domes last for centuries, but Superadobe can also form rectangular shapes.
History
The technique’s current pioneer is Nader Khalili who originally developed the Superadobe system in 1984 in response to NASA call for housing designs for future human settlements on the Moons & Mars. His proposal was to use moon dust to fill the plastic Superadobe tubes and Velcro together the layers. In 1995 fifteen refugee shelters were built in Iran, Nader Khalili and the Uniteted Nations Development Programme (UNDP) and the United Nations High Commissioner for Refugees (UNHCR) in response to refugees from the Persian Gulf War. According to Khalili the cluster of 15 domes that was built could have been repeated by thousands. The government dismantled the camp a few years later. Since then, Super adobe method has been put to use in Canada, Mexico, Brazil, Belize, Costa Rica, Chile, Iran, India, Siberia, Mali and Thailand ,as well as in the U.S.
NEW APPROACH TO SANDBAGS
Common sandbags and connecting barbed wire, as well as mile-long bags, are referred to as Superadobe construction. For centuries, sandbags have been used as elements in building temporary dikes and protective walls in combat zones, as well as in numerous lesser applications. After the structure has served its temporary purpose, the sandbags normally are removed, emptied and discarded. Superadobe building system builds on three fundamental aspects of historical sandbag modules, resulting in a permanent system of construction:
The most serious drawback in the past concerning sandbags as a structural element is that a stack of bags has no tensile capabilities, which has kept structures very low in height. Also, curved, arched or domed structures were impossible without some friction and tensile resistance available.
Superadobe uses four-point barbed wire (or a similar element) between sandbag layers, allowing one to develop the tensile and shear capabilities that have not been previously achievable. The barbed wire element increases the friction factor between the bags and creates tensile resistance in a wall or structural element. It is an important aspect of Superadobe to provide for the transfer of shear stresses from one sandbag to another by using the barbed wire as an interface between the bags, overcoming problems of low shear capability in the earthen fill. The increased capacity of the sandbags, achieved by using barbed wire, creates the capability of designing higher walls and curved surfaces, such as bearing walls, arches, domes and vaults.
Previously, sandbags were not considered part of a permanent structure due to the use of loose fill material, usually sand, which can be loaded easily and discarded when the temporary structure is no longer needed.
Superadobe fabric tube or individual sandbags are packed with different mixes of fluent, particulate material. These include earthen, cementitious, organic, manufactured and recycled materials that form into a permanent block.