This is a fascinating project but I’m always frustrated when they don’t share the formulation of their materials. Looks like a lot of reinforcement. A major downside to modular geodesic construction is the number of seams that invite leakage over time. A more monolithic application of a slower-setting material over a frame would be preferable to me.
Having experimented with a lot of concrete composites I’m always looking for the sweet spots of frugality, obtainablity, practically. This appears to be some geopolymer or magnesium cement -fairly exotic materials for me. Geopolymers often require a strong alkali to set. Not a huge fan of Portland, but at least it’s obtainable and relatively inexpensive for sustainable use cases.
Ask Appalachia about company towns. Folks here at least ought to know better.