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Keeping you informed about the TecEco cement project. Issue 30, 29th November 2003
I apologise to our readers for not sending out a newsletter earlier. My excuse is that I have have been traveling in Europe and Asia attending conferences and setting up research projects and just did not have the time. More recently I have not been so well with a cough I just can't seem to shake off.
We were hoping to have the newsletter automated by now. At this stage it is a manual unsubscribe so if you don't like hearing from us please just send us an email to that affect and we will delete you from our address book. What this will mean however is we loose touch with you altogether.
One of the more enjoyable aspects of this project is the large number of people I have met and friends I have made. Thank you all of you including my relations Gerald and Ellie, Rosemary and Mavora, Adrian and Maya who had me to stay whilst in the UK, Abir Al-Tabbaa at Cambridge and many others. Whilst in India I stayed in Ajay Singh's Club and was shown around New Delhi. Thanks also to Orind for looking after me in Pune.
Rob Cameron, a young engineering graduate has done a great job looking after our interests in the UK. A Tasmanian by birth Rob has now relocated to Melbourne where he will continue his involvement with TecEco.
It's all happening!
I returned from speaking engagements in Singapore, Dundee (UK), Leeds (UK) and Pune (India) at the end of September and have been administering research projects around the world that have been particularly engaging and that have more recently focused on TecEco Tec-Cement concretes (previously called modified Portland cement concretes).
TecEco Tec-Cements are getting more strength earlier with less cement - even with added fly ash! So watch out for an important announcement about Tec-Cement concretes soon. They are shaping up to be a benchmark in cement science.
A couple of days ago for example we received a communication from a NATA laboratory saying that one of our Tec-Cement mixes had achieved 19.5 MPa in 6 days and 26 MPa in 13 days with only 245 Kg OPC/m3, 30Kf MgO/m3 and 25% fly ash. Not bad ??? A previous test batch reached nearly 50 MPa in 60 days. I suspect this current batch will go even higher.
The strength gain is probably due to a couple of factors - lowering the water binder ratio and possible super saturation of Ca(OH)2. If we are raising the pH a little then we are getting a much more affective and possibly polymeric pozzolanic reaction (Roman cement?).
We are still experimenting with plasticisers. Ligno sulfonates do not seem
to work. Polycarboxylate and other types are still to be tested and if they
work we should get even more rapid strength gain, lower binder content and sustainability.
We will make an announcement about Tec-Cement concretes soon when we have received more third party confirmation.
Probably the biggest problem in the construction industry is the lack of training given to those on the job. Hopefully this will eventually change. As change is unlikely in the short term readers will be interested to know that TecEco cements are much more forgiving of abuse. For example the above batch was over watered to 100 slump by the operators on the day and yet we are still achieved excellent results.
Last Saturday there were a group of concretors on an experimental job who expressed a preference for our concretes. They were using ordinary concrete and it bled a great deal of water during the plastic stage. They demanded our concrete which they had used a couple of weeks earlier and I don't even know their names!
The fact that the finishers love Tec-Cement concrete will help win over the market.
It is essential that all our research partners realise that a better understanding of the chemistry is essential prior to developing testing programs as this will save time and allow the formulations to better express the advantages of the unique mineralogy. I accept that doing so at the moment is not so easy as my own understanding is improving daily and the chemistry document on the web is not up to date.
With a sound knowledge of the mineralogy of brucite, magnesite and hydromagnesite, formulation strategies for the use of reactive magnesia in binders are more likely to succeed. A good text is Deere Howie Zussman. I also strongly suggest readers download (in a few days) the latest version of the technical presentation (www.tececo.com/technical documentation) as I will update it and keep it current (mainly to remind myself of things to write about!).
Reactive magnesia expresses as two different minerals as does Portlandite. In the case of TecEco cement technology, the hydroxides and carbonates of magnesium are more useful because of their mineralogical properties. So far three main formulation types have been discerned.
When developing formulations it is very important to:
Eco-cement concretes were designed for block making and must carbonate to gain strength. Bricks, blocks, pavers, mortars, pervious pavement (see our newsletter 29) etc. are generally permeable and therefore can carbonate and as they make up a high proportion of the built environment the impact of using Eco-Cement technology will be considerable.
To fairly test Eco-Cements block formulations should be used as that is what they were designed for. To test something in a manner for which it is not designed will not deliver meaningful results. As making blocks is quite an art it may be necessary to consult a block maker if the relevant expertise is not "in house". TecEco are lucky in that one of our shareholders is a block maker and very experienced at his trade.
If readers are contemplating doing their own research I would highly recommend they run formulations for experiments past us before doing them as I will then hopefully be better able to point them in the right direction. At this point in time I have made at least five hundred formulations that I have documented and the more recent ones have been for up to 20 cubic meters of concrete at a time. (Large pours have been very useful in gaining further understanding of the properties inherent in reactive magnesium based cements.) This experience will undoubtedly be of use in helping your project achieve its aims.
In the take-make-use-waste society that we live in what we take from the "biosphere" to sustain ourselves and create and power our "technosphere" eventually ends up as "waste" that must be assimilated by the "biosphere". By carefully selecting what we take we can control how long utility (usefulness) is maintained and therefore how long these resources are kept in the technosphere and not returned to the biosphere in an altered and often polluting form. In this sense the materials we use and molecules that comprise them are the key to a more sustainable environment.
Using more or the right inputs in a sustainable manner and manufacturing with final use or wastage in mind will reduce outputs the biosphere can no longer handle without undesirable consequences such as global warming and pollution.
The built environment is our footprint, a major proportion of the technosphere and our lasting legacy on the planet. In this dominant proportion of all materials flows unsustainable practices abound from the logging of old growth forests to the high volume of wastage at landfill.
The challenge embraced by TecEco is to create materials that have comparable if not superior properties, that maintain greater utility longer and do not have to be down or out cycled, and that result in less outputs to the biosphere that cannot naturally be re assimilated
According to an RMIT university (Australia) press release "new research is showing that careful materials selection can reduce the energy required to construct buildings by more than one third and that materials specification is crucial to indoor air quality, well being and productivity"
It is imperative that we understand the importance of materials as the key to sustainability.
The Federal Government of Australia has announced an inquiry
Sustainability of Australian Cities (House of Representatives Committee
Inquiry on Sustainable Cities 2025).
TecEco wish to point out to the enquiry the importance of careful use of materials and in particular their embodied energies, affect on lifetime energies and CO2
emissions on a life cycle basis if greater sustainability in the built environment is to be achieved. This is very important and bigger than just TecEco. As a consequence we are looking for help to write the submission as it would be better if it did not just focus on TecEco cements.
The terms of reference are at: http://www.aph.gov.au/house/committee/environ/cities/tor.htm
and are summarised below:
The House of Representatives Standing Committee on Environment
Heritage will inquire into and report on issues and policies related to
the development of sustainable cities to the year 2025, particularly:
* The environmental and social impacts of sprawling urban development;
* The major determinants of urban settlement patterns and
patterns of development for the growth of Australian cities;
* A 'blueprint' for ecologically sustainable patterns of
with particular reference to eco-efficiency and equity in the
provision of services and infrastructure;
* Measures to reduce the environmental, social and economic
continuing urban expansion; and
* Mechanisms for the Commonwealth to bring about urban
reform and promote ecologically sustainable patterns of settlement.
Submissions to the Sustainable Cities Inquiry are to be made
Perennial, or year-round, sea ice in the Arctic is declining at a rate of nine percent per decade and in 2002 summer sea ice was at record low levels. Early results indicate this persisted in 2003. If these melting rates continue for a few more decades, the perennial sea ice will likely disappear entirely within this century.
Anybody out there still believe that climate change is not reality?