The concrete industry is well known for its 'less than impressive' environmental impacts; it constantly emits significant amounts of CO2 mainly through the processing of its raw materials. And yet, it is currently indispensable to the way the building industry operates. Of course, worldwide, attempts are being made to off-set key material ingredients in the production of concrete in order to lower the impact of CO2 emissions and, at the same time, maintain structural standards. The use of alternative binders such as geopolymer, along with alternative aggregates like hemp, kenaf, basalt fibre, carbon fibre and char are just a few of the ingredients currently being researched. Each alternative material has its own history and qualities, and each provides potential for the production of Greener concrete.
In the Byron Bay Shire, Northern NSW, Australia, there is currently a drive to improve new housing development through the use of greener concretes, particularly by utilising industrial hemp as a viable structural material. For the last few years, at Byron Eco Park, initial research has been underway to find ways of utilising hemp to create a structurally sound concrete that is lightweight, less labour intensive, and greener than traditional concrete (greener insofar as it acts as a CO2 sink). The information below is an outline of some of the results.
Buildings and Pilot Plant
For some time now, a major Eco village development on the grounds of Byron Eco Park has been in conceptual planning. The Eco village, or 'the Hill Development' as it is known, is a plan to build a substantial number of eco-tourist dwellings overlooking the ocean views of Byron Bay, using various innovative designs. Earth sheltered dwellings interspersed with tree-top cabins are among the priorities. The development will include a 'well-being' centre and restaurant, conference areas etc.
Importantly, the eco-dwellings are intended to be built on site at the proposed Eco-Crete pilot plant, located in the industrial area among the existing green buildings at the south western end of the property. Ecocrete is composed of hemp, basalt fibre, char and cement; it is lightweight, fireproof, and, importantly, is a CO2 sink. The Eco-Crete Pilot Plant is currently in the first stages of development: plans have been drawn and foundations are in place. The Eco-Crete Pilot Plant is large enough to house the possibility of 3D printing.
Above: Dieter Horstmann demonstrating fire resistant Ecocrete hemp/cement building material. A slab of Ecocrete is placed directly on a gas burner for 20 minutes - not flammable and no transfer of heat. Demonstrating it's value as a low-cost, extremely strong and light building material for constructing housing - especially in bushfire prone regions.
Above: Ecocrete after 30 minutes - placed directly on a gas burner flame.
In the manufacture of Ecocrete:
100% Replacement of sand and stone rubble/pebbles with woodfiber CO2 materials, incorporating Hemp chips, bamboo fibre, wood chips, kenaf chips, all suspended in a liquid solution, reducing shrinking during drying process.
(Kenaf (Hibiscus cannabinus L.) is a fiber plant native to east-central Africa where it has been grown for several thousand years for food and fiber. It is a common wild plant of tropical and subtropical Africa and Asia. It has been a source of textile fiber for such products as rope, twine, bagging and rugs.)
Manufacturing process: as casting, spraying 3D printing, saving labour construction costs (the biggest cost component in contemporary housing construction - showing a way forward for affordable housing solutions).
Ecocrete has several advantages over conventional Concrete:
- excellent noise and heat insulation, not flammable - bushfire resistant
- much lighter, enabling new forms of design, while retaining the same strength as conventional concrete
- the world's first real “green concrete” - works as a CO2 sink
Current Testing in steps:
- testing for optimal chipsize for application
- wood liquid “bleading” process if required for optimal liquid solution treatment by dipping or autoclave.
- ways of drying, developing “crystalline” reaction in wood fabric.
- developing machinery equipment for industrial manufacturing in Pilot plant ; new product brand, just add special cement and water.
- Controled and authorized by BAM Berlin, Pilot plant at ByronECOpark by Cement manufactor under license from CH Foundation.