Jay C. White Cloud wrote:Not to be contrary John, but the "matrix" of a domes physical context has little to do with it's tectonic integrity as long as that matrix is of "sound" composition, whether in block or some other extruded and/or malleable material, such as cobb.
jay
Ah, but it does, Jay. That matrix needs to harden up to its ultimate strength, that's why bricks get fired to speed the process along (plus surface vitrification is a big help). Or if you have plenty of time, you can wait for concrete blocks to obtain their ultimate strangth, which takes 30-50 years or so. Since that takes so long, it's better to spend your time quarrying blocks (which have taken geological time to harden up), stack them up until you can put a keystone at the top, and hold the whole thing together with a cementitious mortar. Even then, when the ground starts shaking, cracks are going to show up at the weak spots, which are the mortar joints.
While I would be queasy in a newly finished cobb dome, I have nothing but admiration for cobb/adobe/rammed earth/"matrix" constructions that have completed their chemical reactions and stood the test of time: