When I go looking for news of sustainable development, PC Magazine isn't the first publication that comes to mind... Perhaps I should rethink that, as on Thursday, they took note of the finalists in the History Channel Modern Marvels Invent Now Challenge. At the top of the list: the Strawjet, a new green building material that takes advantage of straw's advantages while shoring up its weaknesses: "The Strawjet processes straw that's left over after harvests into a mat, similar to a very large bamboo window blind, which can be used to construct eco-friendly composite building panels." Unfortunately, that's about all they say about this "Modern Marvel," but the project's website has a ton of information on the process that went into developing the Strawjet:
As the site notes, Strawjet produces a number of environmental advantages, including the use of material generally considered waste, an increase in insulation and even carbon sequestration. It looks the production team is still tinkering with their creation, but the corporate website notes plans to begin large(r)-scale production by 2008.
The desire to use straw as a building material is as old as the agricultural revolution, but straw based products have always suffered from the apparent lack of strength of the plant itself. Previous technologies from straw bale construction to the recent development of compressed straw-board and straw panels have all begun with crushed, chopped straw. The fundamental advance embodied in the Strawjet technology is the use of the whole undamaged plant stem. The compressive strength of straw when loaded parallel with the stem is impressive. The Strawjet system seeks to use that strength by bundling the plant stems into "cables" about 2 inches in diameter.
These cables can then be combined to form individual construction members or into panels or entire wall systems. To be compatible with the demands of the U.S. building industry to reduce labor costs at the building site, a panelized construction system is being developed using cables woven into a continuous mat. (see: how it works) A wall is built up by laminating successive layers of mat together with a binding material primarily made of clay, soil and paper pulp. Alternate layers are oriented at right angles to provided strength along both directions.
Categories: greenbuilding, innovation, straw, invention,