[GSBN] Reinforced Monolithic Adobe (Cob) Seismic Testing almost done- tax deductible donations welcomed

[Art Ludwig-Oasis Design]

Kyle, 

There are many other reinforcement regimes we would have loved to include. Alas, for this pass we had to eliminate many worthy contenders. 

Here in So Cal, steel seems to very quickly get a film of rust in the fresh, wet cob…then not corrode much more in the 10 years or so we’ve been eyeballing it. 

Straw/ bamboo doubtless would last longer, but would not get us anywhere near the 7500 lbs/ linear foot we’re shooting for. This is an insanely high level of resistance; it is likely that even with a double layer of 94,000 psi steel mesh anchored top and bottom in concrete that we’ll fall short of this (USGS says our area can have 2 g of lateral movement…speaking of insanely high).

I suspect that bamboo is the optimum material for a purist who needed modest resistance. I think even modest resistance would require attention to bamboo joints in tension that is far beyond what I know how to build.

The straw-only wall is intended to test base isolation.base isolation  could be a zero-concrete “purist” system that works even for high earthquake areas like ours, thanks to the load reduction of base isolation. (This is totally speculative, our two consulting engineers are skeptical.) More testing needed…but meanwhile this is what we were able to do in terms of moving the ball closer to the goal post.

Peace,

Art


Pure monolithic cob on top of gravel, with one steel band around the base. Not suited for areas where “high boots” on walls are needed , but no boot structures have worked in this climate.

> On Dec 29, 2018, at 2:43 PM, Kyle Holzhueter <nihondaigaku.kairu at gmail.com> wrote:
> 
> Dear Art,
> 
> Great work! 
> I'm curious why bamboo isn't included as a reinforcement method. I understand it's probably less predictable than steel, but I suspect it's also less susceptible to degrade in earthen walls. My understanding is that, in concrete walls, steel tends to corrode as the concrete neutralizes over time. In Japan, it's not uncommon to find completely corroded steel, like wires and nails, in earthen walls. It's also not uncommon to find pristine bamboo in 100 year old earthen walls.
> 
> Kyle
> *************************************************
> Kyle Holzhueter  PhD
> First Degree Certified Plasterer
> Permaculture Center Kamimomi
> Architectural and Regional Ecological Design Studio, Nihon University
> 
> カイル・ホルツヒューター　博士（生物資源科学）
> 一級左官技能士
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> 日本大学大学院　 建築・地域共生デザイン研究室
> 
> Mobile: 080-3477-9841
> http://holzhueter.blogspot.com <http://holzhueter.blogspot.com/>
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