This post by Patti Stouter is part of a larger effort to summarize existing test results and hopefully organize and conduct more earthbag tests.
“During 2010 and 2011 engineering tests of earthbag increased. Universities involved in evaluating earthbag structures have ranged from Ghent, Belgium, to Cape Town South Africa to Stanford and Brown Universities. Test walls have been recently built by University of Cincinnati students and University of Bath students.
The understanding of earthbag construction is improving. Many tests have used moistened, tamped bags. Testing has involved tall stacks of bags and full walls. But to date almost all testing has involved the use of non-standard sand as fill.
Sand fills have an important place for flood-resistant planning. In some locations sand bags may be the best way to build. But sand bags are not earthbags. The functional characteristics of standard earthbags filled with subsoil that contains clay must be also explored. Fill containing clay creates stronger structures. Adobe based on clay has been the standard building material for millenia. Earthbag is a technology based also on the strength of the clay that acts as a binder in most subsoils.”