Hempcrete cast on top of concrete? Blasphemy or genius?

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Жыл бұрын

MNBC (a French company) has developed and deployed an amazing concrete and hempcrete hybrid modular build system that has been in operation for over 10 years. In this video we will look at three projects all using this hempcrete system. What changes to this system could there be? Replacing concrete with geopolymer would lower the foot print even more than it is. #hempcrete #hemp #hempcrete #hempbenefits

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@charlesfeng3823 4 ай бұрын

Will condensation BTW concrete and hempcrete be an issue

@nc3826 Жыл бұрын

It's not blasphemy, but in terms of where the concrete meets the Hempcrete. I would have some concerns about condensation and moisture buildup? Due to the gradient differences in permeability. I wonder if moisture probes or via moisture meter have ever been used to test this issue? But overall it seems like a very efficient and effective way to build with concrete and hempcrete. For multi-story buildings. And if I was going to modify the formula I would consider adding a foaming agent such as the surfactant to the Hempcrete to increase its insulating value. The non-standardization of geopolymers and its chemical makeup, Would be somewhat of a health concern. But Hempcrete ICF block construction, seems more conducive and unless capital intensive for smaller structures. Lastly, the terminology is a little bit past my full comprehension, but it was an interesting post on Hempcrete construction. So thanks for posting it.

@hempknowlogy Жыл бұрын

The wall system was tested before any actual installations were done. some of these are over ten years old. The French are anal about testing structures in all manner of builds cob/wattle and daub (torchis), Rammed earth (pise) etc. Hempcrete like Cob structures absorb and slowly release moisture modulating the humidity. It is the single most unique factor in determining "comfortable" feel in a home or enclosed space. In reference to geoploymer, most but not all research papers on geopolymer used fly ash, silica fume, GGBFS Ground granulated blast-furnace slag, as the precursor. Precursors are pozzolanic materials that have all have concentrations of alumina and silica and react accordingly however there is a less toxic path according to Joseph Davidovits. I can post on that subject later. ICF have potential but still need RC (reinforced columns) concrete in rebar. Much like old cinder blocks now called CMU or slump brick. They all required RCs. HempBlock USA needs RCs and a concrete bond beam.

@nc3826 Жыл бұрын

@@hempknowlogy First thank you for the response. Apparently I was not clear in what I was trying to say. My concern is at the "boundary layer" between moisture-laden hempcrete and the less permeable concrete. While there's a possibility that moisture can be transposed to the exposed side that's not a foregone conclusion. Depending on the conditions the exposed side of the Hempcrete can dry out, while the boundary layer can have a high moisture content. That over decades a deleterious condensation / moisture issue could possibly occur. You were saying that the French have done decades long testing? i'm sure they check it initially but it's a little hard to believe they have done decades long testing for a process that doesn't seem to be that old. But if I'm making an incorrect assumption please correct me? And I'm just probably being overly cautious in any case. But it's always good to have long-term testing just to be sure. Also I'm aware of everything else that you stated. But of course ICF hempcrete blocks need reinforcing bar in the columns and beams, just like in other forms of ICF construction. FWIW HempBlock USA is an Australian company that obtained a French license to market it in the USA .... Since it is a French patented design.... Hempcrete and other forms of cellulose/cementitious hybrid construction. Seem to be at a turning point in the construction industry. So it's fascinating to see how it's evolving. Thanks for the feedback and keep up the good work.

@JaSon-wc4pn 10 ай бұрын

I've seen examples of the rammed earth into car tyres to build an ecohome into the side of a hill. Shared the came "comfortable" factor, storing heat then releasing it. Truly fascinating

@nc3826 10 ай бұрын

There are more things in heaven and earth, than are dreamt of in your philosophy....

@user-uv2uo1gk1k Жыл бұрын

Thank you so much for all of your content! I am thinking of using hemp or straw to build a house, and my first thought was that tilt up construction could save quite a bit of time and labor. I have seen prefab panels of straw, (eco cocoon etc) but not hempcrete until I found your channel. Do you know of anyone using a lime binder with straw instead of hemp? Straw is much cheaper to source in the US, and I am wondering if it would be suitable. Thanks for all your great videos!

@hempknowlogy Жыл бұрын

No problem:) I know of one that did it near Smithville Tx (i think) that being said I just posted a video of sprayed clay and hemp, a sprayed cob if you will. I would think you could use the same technique using chopped straw. It would have to be short maybe inch in length. FYI An interesting alternative used in France is Typha (cattail)