Earthbag archway approach: layers vs monolithic curve

Oct 24, 2020 15:35:22

Can hyperadobe be used to create continuous arches? What I mean is making a form from 2x4's with some kind of arch on top, then extruding the raschel mesh over that support in a continuous line and letting it dry. As opposed to the wide, short courses one would usually do, the arch would only be a few inches thick. But it would be one unit with no seams, which seems to me might be strong enough. The advantage is you'd use far less materials and time. The disadvantage is you couldn't add windows. But for a quick-and-dirty hallway it seems like a faster, cheaper way to go. If it wouldn't fall down and kill you. Thoughts?

Please excuse the crudity of this drawing

Oct 24, 2020 19:32:26

It would be more material-efficient, but it would also require much more precise load calculations to keep the arch in exact relationship to the force distribution. The thick earthbags will stand up as long as the actual line of force falls within the 20" thickness you show, which is pretty easy to get intuitively. A thin arch which does not have great bending strength must follow the line of force or it will fail. If it is well reinforced, it can tolerate some deviation from ideal. An arch with equal total thickness of material needs to be a catenary shape for proper load distribution. If the thickness is not uniform (such as bermed sidewalls), calculations can be very complex. Antoni Gaudi was one of the greatest users of organic arch forms.

Oct 24, 2020 19:55:22

I understand! Thanks for that clear explanation.

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