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Bond, Zeobond

November 2012

  • Michelle Gallaher

A Melbourne-based company is leading the way in geopolymer cement research, allowing for the development of ‘green’ concrete that works to reduce carbon emissions.

Concrete is the second most used material on earth – second only to water.

Most of us live in a concrete jungle, surrounded by buildings, roads and bridges.  Living in the city isn’t always easy as trees fight for space against widening roads and freeways and many of us suffer the psychological impacts of living in built up environments devoid of greenery and living spaces. Neuroscientists for years have worked in urban design to try to improve the social impacts of urban environments.  As a society we are rightly concerned about urban sprawl and important role of parks and gardens on our mental wellbeing as well as our city’s environmental health. 

Now for a moment, imagine a world in which the construction of concrete toll roads and city buildings were actually helping the environment by capturing carbon dioxide emissions. Would that fact change the way we feel about urban development?

Cement manufacture causes environmental impacts at all stages of the process, both to the landscape and to the air quality. The cement industry is one of two primary producers of carbon dioxide, a major greenhouse gas. Concrete is used to create hard surfaces that contribute to surface runoff, which can cause heavy soil erosion, water pollution, and flooding. Concrete is a primary contributor to the urban heat island effect, but is less so than asphalt. Concrete dust released by building demolition and natural disasters can be a major source of dangerous air pollution. The presence of some substances in concrete, including useful and unwanted additives, can cause health concerns due to toxicity and radioactivity. Wet concrete is highly alkaline and must be handled with proper protective equipment and the process of quarrying scars landscapes and drastically changes environments for flora and fauna.

A Victorian company is leading the world having developed an award winning new geopolymer cement that reduces carbon emissions to one fifth that of conventional cement. The difference between this new green concrete and traditional concrete is the use of geopolymer technology. Geopolymers are a type of inorganic polymer that can be formed at room temperature by using industrial waste or by-products from coal power plants and steel manufacturing as the binding agents. Traditional concrete is made with ordinary Portland cement that contains calcium silicates from limestone. Processing the limestone creates very high levels of carbon emissions. 

Professor Jannie van Deventer is a world-leading expert in geopolymer technology and former Dean of the Engineering Faculty, University of Melbourne. Her vision was to develop a practical, affordable and effective solution to creating a sustainable alternative to the manufacture of cement, one of mankind’s most polluting activities. Van Deventer established Zeobond in Melbourne to do just that.

Today Zeobond has owned and licensee operated manufacturing facilities in Victoria, Queensland and Western Australia and green concrete is revolutionising the building industry.

Zeobond philosophy seeks to address national priorities of tackling the challenge of climate change by reducing greenhouse gas emissions, recycling industrial by-products and keeping Australia at the forefront of green research and development activity. Zeobond without doubt is in a strong leadership role with E-crete being used in a number of countries around the world after only a few years of commercial operation. Zeobond’s green credentials are impressive. The company is a member of the Green Building Council of Australia’s Expert Review Panel for Concrete, setting the bar for what constitutes sustainable concrete in Australia. 

One of the more fascinating aspects of Zeobond’s research and refinement process in developing the product was using Melbourne’s Synchrotron beamline to analyse various artificial geopolymers to understand the properties and behaviour of geopolymers and how they form hardened gels that make concrete strong. The concrete was tested in a fire furnace at the Fire Engineering Facility of Victoria University to independently confirm that it was twice as resistant to fire as traditional concrete.

According to the International Energy Agency, the manufacture of cement produces about 0.9 kilograms of CO2 for every kilogram of cement. Around five percent of global CO2 emissions result from the concrete manufacturing is process, making it one of the more polluting activities undertaken by mankind.  This is due to the energy used in production as well as the chemical reaction of the cement itself, which emits carbon dioxide. 

Zeobond also partnered with VicRoads to monitor the product in public places. The partnership with VicRoads has been crucial to increasing confidence in using green concrete for Melbourne’s public infrastructure. As the asset owner of Victoria’s road infrastructure, VicRoads has stringent guidelines and standards to ensure the safety of Victorians. 

VicRoads is also working with Zeobond to use and monitor green concrete in various high-profile but low-risk projects, such as footpath works in the Westgate Freeway upgrade. The results of the monitoring in signature public works has been such a success that VicRoads has changed their standards for general paving to include green concrete for use in footpaths, kerbs and guttering. 

Zeobond is now working on a project to develop and test precast concrete segments for tunnels. Already green concrete is providing superior resistance to chemicals and the replacement of steel reinforcing with plastic fibres should reduce corrosion over time. If successful the product use can be extended to marine and other corrosive environments such as outflow pipes for desalination plants and subway systems. 

The success of Zeobond in Australia has generated interest from the rest of the world. Zeobond is now in discussions for a large project in China to reduce carbon emissions and to add value to their considerable industrial waste that can be used to provide the geopolymers. 

The research and development that is being invested in new construction materials with green credentials is considerable. The market will demand it. City dwellers from Melbourne to Shanghai are increasingly concerned about urban environments and seeking alternative construction and building materials that will contribute in a positive way, not a destructive one. Not just in cities, but in their own backyards.

Michelle Gallaher is Chief Executive of the BioMelbourne Network.
biomelbourne.org
zeobond.com

 

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