Two weeks ago I attended the excellent 1st International Rammed Earth Conference in Perth, Western Australia. This was the result of 18 months hard work by Dr Daniela Ciancio and Dr Chris Beckett, who are heavily involved in research at the University of Western Australia in Perth.
The conference was a meeting of rammed earth contractors, designers and researchers from all over the world who met to discuss the finer points of rammed earth for four days. I was in my element.
Perth, and Western Australia are held up as an example of the best of stabilised rammed earth construction, and we were able to visit the fantastic Church in Margaret River, and some wineries with rammed earth buildings. It's clear that Stephen Dobson and his contemporaries have carved a superb rammed earth niche in this corner of Australia.
We were also treated to David And Taj Easton from Rammed Earth works and Watershed Materials. David has been at the forefront of earth building for over 30 years, and continues to innovate with new materials and techniques, as his collaboration with Joe Dahmen in Watershed block really shows.
Meror Krayenhoff has revolutionised rammed earth building in colder climates through his SIREWALL system of insulation between rammed earth leaves, and Meror shared his experiences and visions using this system.
The conference also featured many speakers exploring the thermal and humidity behaviour of rammed earth. There is an amazing body of work exploring the hygrothermal mechanisms at play in rammed earth. It is through understanding and measuring these mechanisms that we are able to use the material most effectively.
There were a selection of papers on taking rammed earth buildings through the building consent process, with speakers sharing their experiences in Canada, the UK, Australia and New Zealand, with a wide range of experiences from remarkable simplicity to years of drawn out negotiations.
My overwhelming thoughts at the conference were of optimism for rammed earth building, a commitment to maximising and improving the sustainable credentials of rammed earth, but an acknowledgement that further research is required to better understand the predict the behaviour of rammed earth.
I certainly picked up that rammed earth has the ability to transform to suit the environment in which it is built. This was shown by a fantastic presentation from Rongrong Hu whose amazing work at Xi'an University who showed the variations in rammed earth across China, where the rammed earth wall thickness appears to change depending on the climate, and where in warmer climates, one of the walls is replaced by light timber framing.
This versatility is also found in modern rammed earth, exemplified by the different approaches of David Easton in California and Meror Krayenhoff in the colder British Columbia whose SIREWall system places insulation between two leaves of rammed earth.
I'm a structural engineer, and we learned from Bill Smalley how engineers in Western Australia have treated rammed earth, and from Tim Krahn about his experiences with structural engineering in Canada. There is still room for improvement in the structural understanding of rammed earth, and the large scale tests carried out by Daniela Ciancio and Chris Beckett at UWA, and by Venkatarama Reddy and his team in Bangalore are really pushing forward the understanding of rammed earth as a building material. On the modelling front, Quoc Bao Bui showed cutting edge Discrete Element Method analysese of rammed earth and looked at the creep behaviour of rammed earth.
At the other end of the scale, the microstructural behaviour of rammed earth is being researched by the team at Durham using their new X-Ray Computer Tomography machine, and we were treated to exciting presentation about the inside of rammed earth from Joe Smith.
Perhaps the most inspiring presentation was from Joe Dahmen who showed some new innovations which might be worked into rammed earth, such as using microorganisms to grown cementing compounds at Biomason and I also like the the 3D printed blocks which Ron Rael has recently produced.
I'm really excited about the direction rammed earth building seems to be heading. There is still plenty of research and learning to be done, but there are also those who have been successfully building rammed earth for nearly 30 years. The material with a rich and varied past has a great future ahead.