Martin Ernegg of Synergetic Systems Inc, Nimbin, is creating building materials made from valuable weeds and magnesia cement, for example lightweight bricks, flooring composites and insulation panels, which store carbon (weed chips) within magnesia cement, over a long period and is a viable way to manage these plants.
For northern NSW Lantana, Tobacco Tree, Giant Devils Fig, Coral tree, Camphor laurel are of great value for Weedblocks.
Magnesia Cements (also known as Sorel cement) is a non-hydraulic cement which can replace the use of the traditional, energy intensive Portland cement.
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The Weedblock project:
The rapid urbanisation is creating a shortfall of conventional building construction materials due to limited availability of natural resources. On the other hand energy consumed for the production of conventional building construction materials pollutes air, water and land. In order to meet the ever increasing demand for the energy efficient building construction materials there is a need to adopt cost effective, environmentally appropriate technologies and upgrade traditional techniques with available local materials.
Weeds are problem species that interfere with our natural habitat and agricultural productivity. This results in these plants being eradicated without regard for their other ecological and economic importance. Some weeds have properties that make them highly suitable for building applications, especially in a “weed –magnesia cement composite”. For northern NSW and southern Queensland Lantana camara, Tobacco Tree, Giant Devils Fig, Coral tree, Camphor laurel are of great value. Creating local produced, lightweight bricks, flooring composites, insulation panels, etc., that store carbon (weed chips) over a long period, is a viable way to manage these plants. Till now, perception is that the merits of these weeds score much lesser than the hazards. Time is ripe for bending the notion.
To decrease CO2 emissions in the cement industry, new cement-based binders are in the focus of attention, especially calcium-based systems, geo polymers and new magnesia binders. Over the past 170 years concrete based on Ordinary Portland cement (OPC) is the material basis of the construction industry. Next to water concrete is the globally most used material nowadays [1]. During the last decade the global cement industry showed annual growth rates of 7 % and more. A further increase in cement consumption is predicted for the future.
However, climate protection is posing new requirements on cement production and demands innovative solutions:
Magnesia Cements (also known as Sorel cement) is a non-hydraulic cement first produced by Frenchman Stanislas Sorel in 1867. It can withstand 10,000–12,000 psi (69–83 MPa) of compressive force whereas standard Portland cement can typically only withstand 7,000–8,000 psi. It also achieves high strength in a shorter time.
The pore solution in wet Sorel cement is alkaline (pH 8.5 to 9.5), but significantly less so than that of Portland cement (pH 12 to 13).
Other differences between magnesium-based cements and Portland cement include water permeability, preservation of plant and animal substances. These differences make many construction applications suitable.
Made from valuable weeds and magnesia cement by Synergetic Systems Inc, 87 Cecil Street /Nimbin, NSW 2480.
Contact: Martin Ernegg – email: martinernegg@gmail.com
Some weeds have properties that make them highly suitable for building applications, especially in a “weed –magnesia cement composite.”
