Shredded/chipped bamboo as filler instead of hemp in hempcrete

Given that bamboo has a high silca content like hemp, could it not be used as a 'filler' in hempcrete or as I'd call it bamcrete The reason I ask is that in my country (New Zealand) the rules for growing your own hemp are extremely long winded and difficult. Also the way I see it bamboo wouldn't require the stripping of the outer fibre like hemp does. I'm not inteested in making hemp fibre, just a house.

There are people making and selling hemp shiv in NZ, but at a distance that makes the advantages of it rather less.

Any comments / impressions / observations welcome.

I was able to find info on bamboo as a rebar substitute (it works, apparently) but nothing immediately about it as an aggregate. Check out this text: Material For Sustainable Sites - Meg Calkins Page 425-7 in particular. It's written a textbook, but doesn't offer citation for some of the topics covered (the historian in me reels at this)

Who's going to test this out? I think you could really be on to something. . .

Hemp averages ~ 80% silica content since it can grow in sand it is said, so if the bamboo is that high in theory, yes, however, I have never seen any data to support this as in lab of tested core samples. I know Magnesium OXY Chorides bind well to cellulose since I been talking to a MAG chemist and seen his lab test but nothing specific to hemp. Be careful here there are hemp suppliers and myths that would like everyone to believe it is some magic potion. It binds well to lime and portland cement to, perhaps a mag bentonite clay again in theory, but many of the binders can leach and be corrosive if not designed right.

We been talking about tensile strength aggregates here: https://permies.com/t/56689/cob/Cob-Fiber-Composite

Old forum but could not find much els im thinking of giving this a go well making a brick see how that holds up to a test than a wall. Has anyone tried similar

Bamboo has a high content of sílica but most species also have high content of starch. The starch is on the inner part of the culm. That's what the bugs eat in bamboo. One way to get rid of the starch is to soak the culms in water for 30 to 40 days. Running water is even better.
Phylostachys aurea is a species with a low content of starch. That's why it's used to make furniture.

Sergio Cunha wrote:

Phylostachys aurea is a species with a low content of starch. That's why it's used to make furniture.

Different bamboo species can have quite different characteristics. When and how you harvest it also has an impact. I've read that bamboo in contact with the earth rots quickly, and yet I've used P. dulcis in my garden and it's done better than expected. I tend to cut it and leave it to dry with the leaves on, so I'm thinking that may help to use up the starch.

Thanks for the reply i am looking into this because myself brother and farther run a bamboo farm consisting of over 600 clumps however these arv for shoot production. However we still have 20 clumps that could be used for material but i did some calculations and i required 12444 lineal meters of the species most available and thats based on one wall of what i want to build so it looks like a costly labour high excersize currently

Seems to me it ought to work.  I want to try it. Has anyone else tried it?  I figure on chipping it, soaking in water and then doing the boric acid treatment.

DAvid White
South Carolina

If this works, I vote for the name "boocrete" or maybe "bamcrete"?

Lol :)

Watching for others to report back and add new data links on what products and methods are being used.
I have a bamboo forest and use it for a lot of things.  I'm also getting a industrial hemp crop going so I can blend the two together in my crete blocks. I'm anxious to discover more research results.

Hi Tj

Welcome to Permies.

Hi all,

I’m interested to learn more about growing and processing bamboo for producing bamcrete.

Has anyone figured out how to “chip” it to the size needed to create bamcrete?

Hemp stems aren’t chipped actually but crimped to produce the Hurd/shiv and seperate it from the long fiber.

Also, if any bamboo fans can recommend good clumping bamboo species that like wet clay-ie soils and do well in zone 8b I’d appreciate having good advice, and yes I do think I’ll plant on mounds.