Cut Straw Bales for Arch Form

I'm building a 200 sq. ft. bale-cob cottage. I planned in a rather large central doorway about 40" across. I've designed an arch for the door to resist the need for a lintel. I cut out an arch form from scrap plywood with a jig-saw and joined them together with 2 * 6's to the width of my wall. I ended up cutting bales down into 8" segments (about 5 flakes a piece), tied very tightly. My idea is to use them as I would adobe bricks, to stack an arch, filling the gaps with cob as with bale-cob mortaring until coming to a "key-bale" or keystone shaped bale cut 10" on the bottom and 14-16" on top and wedging this shape in. As far as I know, nobody has attempted this form. Whats the thought? Hesitations, excite-tations? I'll post a picture if there is interest.

I would like to see a picture Jim. It will be interesting to see what kind of movement, if any, you get.

I think it worked? It feels solid, but I'm going to wait for a few days for the cob mortar to dry before trying to remove the arch form. I'll let you all know how it pans out. A cob bond beam will run on top if it which I think will help distribute the weight even more so.

The hut looks really good.

Strong work mike. post some more pictures of where your at now, it looks great.

I would be interested to hear how that supports stress in various directions. If there is even a little compression in any direction I would be concerned about collapse. I am also wondering about the mix of mediums in the way that you used them. What was your rationale? Depending on how it holds up, you may want to try earth bag methods for the entire doorway and arch, it would be a relatively easy fix to tie it into the surrounding structure. Hope things works as is though....but sceptical.