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Keeping you informed about the TecEco Cement and Tec-Kiln projects. Issue 40, 24th October 2004
Friends of TecEco in the UK interested in the practical application of tec and Eco-Cements should try and get down to to visit Earthship Brighton which incorporates TecEco technology.
There is an open day on the 29th October 2004, otherwise contact:
By Taus Larsen, (Architect, Low Carbon Network Ltd.)
The Low Carbon Network (www.lowcarbon.co.uk) was established to raise awareness of the links between buildings, the working and living patterns they create, and global warming and aims to initiate change through the application of innovative ideas and approaches to construction. Englands first Earthship is currently under construction in southern England outside Brighton at Stanmer Park.
Earthships are exemplars of low-carbon design, construction and living and were invented and developed in the USA by Mike Reynolds (http://www.lowcarbon.co.uk/earthships.html ) over 20 years of practical building exploration.
Earthship are autonomous earth-sheltered buildings independent from mains electricity, water and waste systems Earthships homes or offices are off-the-grid with little or no utility costs.
We contacted John Harrison from TecEco Pty. Ltd. over a year and a half ago via email, and he explained the basic concept of magnesium oxide Eco-Cements and we became keen to investigate and utilise some of his mixes in order to reduce our dependence on OPC.
First we had to source some reactive magnesium oxide. Several local companies selling reactive magnesia were contacted in our quest to find a source that matched the chemical properties of the material used by John.
We eventually tested 2 grades, both from CJC Chemicals at Hartpool in the North of England. (http://www.cjcchemicals.co.uk ) and selected Grade: 93/12F.
Test blocks (150mm x 150mm) were made using 1 OPC, 2 MgO, 9 Ballast.
The test blocks were cured on site, out of the direct sunlight or rainfall and undercover for 7 and 28 days. The results were very encouraging, giving us a 7 day compressive strength of 12.1 N/mm2 ( = Mpa).
Many thanks to the University of Brighton (David Harris, David Pope & Ray ) for assisting the testing process. Althought the test equipment was not NAMAS accredited and had not been recently calibrated, it was considered reasonably accurate and sufficient for our purposes.
We had mainly been using the 1 OPC, 2 MgO, 9 Ballast mix as a mortar for bottle walls and other minor works. It was a pleasing mix to work with, stiff yet pliable and workable.
As the Eco-Cement 28 day test gave a compressive strength of 19.6 N/mm2 for 1 OPC, 2 MgO, 9 Ballast, compared with a PC concrete test block (1-OPC: 3-Ballast) of 36.2 N/mm2 and was sufficient for structural works, we decided to use Eco-Cement formulations for our floor slabs from then on. This may have been a risk, but at least a calculated one.
It is important to note that this was in the absence of a pozzolan, and somewhat against the advice of John who had visited shortly before hand. He had recommended we find a suitable pozzolan, preferably class F fly ash, before pouring any structural works and that we use a different mix . The use of fly ash was however considered unsuitable for open mixing by our build crew, as it contained a high level of heavy metals and arguably carcinogenic toxins. Other pozzolans such as brick dust and rice husk were difficult to obtain, expensive and potentially unreliable.
We have since poured all our floors (totalling approximately 90m2) with the above 1 OPC, 2 MgO, 9 Ballast Eco-Cement mix, observing no problems of cracking or shrinkage whilst using only 8-9% OPC. (Ed. note: Evidence that carbonation is occuring include a continuous hardening and strengthening).
We are currently resuming our tests, taking on board further advice from John.
We have acquired a brick dust pozzolan and plan to try a 40-60 Mpa Tec-Cement, taking greater care in sourcing specific aggregates. Hopefully this will result in slabs of comparable or superior strength and durability, with a fraction of the OPC and associated carbon emissions.
In the future we aim to replace all our mortars and concretes with a combination of Tec-Cements, Eco-Cements and carbonating lime mortars in our next build.
Great pioneering work from Taus Larsen, Darren Howarth and Mischa Hewitt and the rest of the crew. TecEco will do all I can to help!
To find out where Stamner park is go to www.multimap.com click on the the south of England and drill down just to the north east of Brighton. The park is very close to the University of Sussex. Drive right through the park and it is just past the old mannor.
As soon as possible I want to write a book about a hollistic blueprint for the future.
I believe that our approach to sustainability must be holistic. i.e. a bit like dieting. The pain of either dieting or exercise is less if one does both. So it is with progress towards sustainability - reductions in energy usage as well as massive sequestration, less rubbish (e.g. packaging) as well as new uses for it are required.
Changes in the technology paradigms defining our techno-world can deliver more sustainable outcomes. New processes that deliver the same utility with less linkage to the geosphere-biosphere must be developed. If durable materials for example incorporated carbon as a basic component as well as many wastes for their physical property then an important, high volume component of the techno-process would require carbon making it a resource. In this way we could mimic nature and consume much more carbon and with complementary reductions in energy usage, potentially one day consume all the carbon we produce, leading to reduced linkages with the greater geosphere-biosphere.
Processes that sustainably deliver the same utility will succeed if economic. The technology paradigm defines what is or is not a resource in an economic system that drives materials flows through the techno-process. By harnessing basic human psychology through cultural change to achieve greater demand for sustainable outcomes delivered by evolving and changing techno-processes that sustainably deliver cost effective solutions economics will define more sustainable resource flows. To be economic new technologies that define more sustainable materials flows must result in increased utility for the ultimate beneficiaries in a system that without inefficient regulation does not recognize externalities.
As we generally perceive ourselves to be the ultimate beneficiaries of our economic if not our entire existence then sustainable materials flows in the techno-process must also be more economic. Put simply, sustainability must be economic or is itself not sustainable.
The TecEco Tec-Kiln, Tec, Eco and Enviro-Cements will have a major role in changing the technical paradigms, in proving that sustainability can be economic and thus achievable.
TecEco will contribute in money and kind to the funding of one or more PhD students provided their supervisors understand that the research must be directed towards providing the background for such a book aimed at those who control global economic policy. If you are interested please contact John Harrison at john harrison at tececo.com. Please replace at in our email address above with @, then write out the address with no spaces between the characters. (Our email address is released in this non-standard format, in order to foil the harvesting software used by spammers to capture the e-mail addresses of their victims.)
The Association for the Advancement of Sustainable Materials in Construction
In conjunction with
RMIT University and the Centre for Design
Innovation || Materials || Sustainability
18th and 19th November, 2004
The Marriott Hotel, corner of Exhibition and Lonsdale Streets, Melbourne, Australia
A conference and workshop with plenty of opportunities to network.
Building focus on materials sustainability, bringing together key groups, networking product and service providers, gathering industry feedback.
How much do materials matter in sustainable construction? How are leading project teams selecting ‘sustainable’ materials? What are the emerging directions in the regulatory sector? What are the needs of the sector in terms of tools, technologies, research and development to make sustainable design easier? Green building is becoming big business and a major policy focus. Sustainable materials have been seen as too hard. But with materials used in buildings alone accounting for over 35% of total materials use in Australia and globally this is now changing. Decisions made by suppliers and specifiers impact profoundly on national sustainability targets.
Architects • Academics • Interior designers• Corporate Real Estate professionals Developers • Economists • Engineers • Environmentalists • Government Clients • Investors • Lawyers • Materials Scientists • Planners • Project Managers • Researchers
• A review of policy and market drivers for designers, clients, and suppliers
• Case-study local examples from leading specifiers
• An review of existing tools
• An insight into future directions in regulation
• To hear from suppliers of innovative products and materials
• An opportunity to provide insights concerning major opportunities/barriers and the incorporation of these into action agendas
• An opportunity to steer the direction of AASMIC
• Workshops exploring and identifying with delegate input the key issues including emerging technologies, research and development, and decision-making
This innovative forum brings together distinguished speakers and experts to present cutting edge developments in sustainable materials and design, raise the profile of the area and to identify the crucial areas for product, tool and policy development as well as a national action agenda for Sustainable Materials in Construction. Professional development points will be available from most Professional Associations.
Please Visit the AASMIC website at www.AASMIC.org.