Geopolymer Concrete, the perfect seasteading material

(.) #62

I am for ferrocement and concrete. There could be other useful materials too.
I also like the biorock idea.

(Wilfried Ellmer) #63

Octavian is of course right - there is not really a discussion on about ferrocement and concrete in marine ambient - the discussion was on at the beginning of the century and lasted until the seventies - since then the discussion is over - anybody who pretends that there is still a discussion going on is a kind of uninformed Umpa Lumpa who has not read the data or has no intelectual capacity to understand what the old data from the the seventies says…for the Umpa Lumpas to sum it up once again with the words of P.K.Metha…

Concrete has clearly emerged as the most economical and durable material for the building of the vast majority of marine structures. Reinforced concrete too has overcome the technological problems making it a suitable material for the construction of advanced marine structures such as offshore drilling platforms, superspan bridges and undersea tunnels. As the world becomes increasingly ocean-oriented for energy and other resources it is predicted that construction activities during the 21st century will be dominated by concrete sea structures. The performance of concrete in the marine environment is presented here in a logical manner giving state-of-the-art reviews of the nature of the marine environment, the composition and properties of concrete, history of concrete performance in seawater, major causes of deterioration of concrete in the marine environment, selection of materials and mix proportioning for durable concrete, recommended concrete practice and repair of deteriorated marine structures. It is of value to any design or construction engineer responsible for marine structures.

Concrete in the Marine Environment (Modern Concrete Technology)
by P.K Metha

@Aquaponic_Dave actually has done some interesting stuff - Dave are you willing show some of this on this public forum ?

Like always it is not about having a versus discussion - it is about to combine all the available methods and materials conveniently - to get a optimized composite that works fine for the purpose it was selected. Heavy methods under the waterline light methods above.


The thickness of a ferrocement hull is usually 1"-2".

At that thickness they are ALMOST as strong as steel.

A ferrocement built boat is about twice as heavy as a same length fiberglass boat.


Ok, 1" - 2", twice as heavy. Drat. I was thinking perhaps running high tensile steel cable in thin non-rusting conduit (of any non-rusting material), and then post-tensioning the hell out of it. Let the conduit (i do not mean electrical conduit) protect the steel cables from rust, and the post tensioned cables pre-compress the cement against cracks. Not sure 2" is thick enough. Heck, even Ellmer says there must be more than an inch over the rebar. I find the problem i am having with cement isn’t the cement itself, or even the steel, it’s using the correct cement, and correctly applying the steel rebar, and not using any fiber that can stretch (hence post-tensioning the steel fibers).


Personally, for seasteading offshore I would build 3"- 4" thick with heavy duty SS rebar and SS mesh or the basalt counterparts that Anenome was talking about. In my view, such hull will last a very long time with very little maintenance.


Use the Basalt rebar and basalt roving. At 40 lbs per roll and much lighter than rebar, you get more strength for the same thickness, or equal strength in a MUCH lighter structure.


That basalt rebar looks pretty cool. Are there any examples of floating structures made that use it?


LOL, does it matter if there are any floating structures made that use it?

I think what really matters here is that FUTURE seasteads could be built using basalt rebar and mesh so they won’t rust, have superior strength and be lighter than the steel counterpart.

But, another “truth of the matter” is that if a seastead will be built @ 4" hull thickness, the basalt rebar and mesh is not needed,…As I said many times here, it’s a waste of time reinventing the wheel in terms of method and construction materials.

Anything “seasteading” (floating that is) under 200’ LOA will be a coastal one and can be achieved by rafting up a couple of houseboats together with concrete floating docks in between them for under $150k. (in a DIY situation)

Same “gig” to be built from scratch will cost 10 times as much. What’s the point of spending 10 times as much for achieving the same result??


That’s a good question. It has to do with what’s the definition of a Seastead.

Let’s say we have 50 people living on a group of floating houseboats, linked together by a $150k dock. Does this constitute a seastead?

How is it any different from a land based set of houseboats. Here in Portland, Oregon, there are something like 3000 people who live afloat in floating communities. Are they seasteaders?

In my view, the key difference in a seastead is not to go “stealth”, but to create an autonomous city-state. To do that means to license and obtain some official recognition. The prerequisite for this is to be very safety conscious. We can’t be licensed as a passenger carrying “ship” without conforming to some very rigorous standards that there be no loss of life. Even after floating, any accidents would be the end of the project. For that reason, I think the engineering and planning needs are high. But that’s a different scope project than you are suggesting.

In my mind, $200 million or so is about minimum for getting an autonomous community afloat, and a good quarter of that is safety and engineering.

(.) #71

For me, seasteading is to be in a minimum interference zone.

Licensing would not be applicable because of no jurisdiction.
So, a kind of off the grid, self-sufficient way of living.

(.) #72

And yes, this could be called seasteading too. Even if it is fresh water.


I would say no. They are just living aboard,…

[quote=“jwliberstead, post:70, topic:240”]
Let’s say we have 50 people living on a group of floating houseboats, linked together by a $150k dock. Does this constitute a seastead?
[/quote]I would say yes if the whole thing is free floating community (not a marina like situation) and if they have a certain degree of self-sufficiency and autonomy, basically the “start up version” of what you called

[quote=“jwliberstead, post:70, topic:240”]
In my mind, $200 million or so is about minimum for getting an autonomous community afloat,
[/quote]And quite a big one,… For that amount of cash you’ll get a go-anywhere concrete floating island with decent accomodations for AT LEAST 2000 people (permanent and/or guests, whatever the percentage), with a marina, public and commercial spaces. Of course, built somewhere in Central America,…


Basalt Rebar…

F.R.T.P. Fiber Reinforced Thermoplastic Polymer reinforcement bar

Price list removed at request of vendor.

F.R.T.P. Fiber Reinforced Thermoplastic Polymer reinforcement bar

SBS<img src="/uploads/default/original/1X/cb3342dfe9e428292e0c9983cfc4535c6b5d6abd.jpg"

width=“386” height=“500”>

F.R.T.P. Fiber Reinforced Thermoplastic Polymer reinforcement bar

Not true. You could put every living human in an urban setting smaller than Texas, at ~14 acre each, free-up prime agricultural land for better agriculture, return the majority of the planet to wilderness and STILL not need a single floating object at sea. 1/8th acre lots, with houses, with proper organization, are providing for the family and marketable sales, as well.

I CAN be done, but it takes work, which has become a dirty word, in the world of gimme-gimme-gimme…


Excepting the WWI barge and WWII cargo ships in use in Canada, as a breakwater…


Lighter than steel, stronger, thinner cross sections possible, non-corrosive, easier to handle… Even the FAO has free, proven ferrocement hull plans… Costs twice as much as identical use of steel rebar, but, at this point, you’re in need of a re-engineered set of plans, anyway.

Hell, everyone on here is discussing ferrocement. That’s the TSI plan… floating cement bases, with everything on top. Guess that makes us all Oompa Loompa’s…

(.) #80

Ooo well, can we just get along.
Basalt and steel rebars do not mind eachothers.

(Dave Pennington) #81

I think the geopolymers are very interesting, and I still need to get up to speed on them. Have they been combined with lightweight aggregates yet? My work (aquaponic system design) led me to develop a super-cheap fiber/cement composite which is essentially papercrete heavily laced with reground waste EPS (aka styrofoam, a misnomer). This material “EPIC” (EPS+paper infused w cement) is very simple to make and has a wide array of uses. In this application it could serve as a cheap buoyant filler inside a geopolymer shell. I would much rather live on a floating box that can’t sink rather than a Titanic type platform which relies on displacement rather than inherent bouyancy.

This new material has opened up several solutions to other problems including energy production water filtration and carbon capture. These projects all are important.