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


Just came across FRTP and it seems to combine the best features of steel and composite rebar.

Like steel, it can be shaped, with minimal internal stress built into the design and reshaped (thermoformed) to accommodate construction techniques. UNLIKE steel, but like other composites, it can be used in conjunction with simple zip-ties. or even adhesives/solvent-cements, and has composite spring tendencies to return to shape, if deformed away from its’ thermally set shape.

As with most plastice, it does lose some strength, in the reheating/reshaping process, but as with most composites, the tensile strength still seems to exceed steel.

The following pdf shows a technique for reshaping, such as forming hooks and eyes in the end of FRTP rebar, meaning bars can be connected end-to-end, in a shear connection, either directly together, or with another piece acting as the shear-pin.


UK Physicist wanting to learn more about seasteading
UK Physicist wanting to learn more about seasteading

(Wilfried Ellmer) #3

@JL_Frusha, i think we need to see the whole picture of marine building methods first - what you do certainly not want on the beginning of a phase1 project is a bunch of “unkown unknowns with new untested wonder materials” that all needs to be tested while the investors sit in your neck questioning everything nerviously opting out at the smalest indicator of “unforseen problems” - we call that a “project setup suicide”… golden rule in phase1 cut down on the unknowns …keep things close to what you have done already and what you know already and your workers can handle already - stay in control - limit the “disturbance factors”. A - F.R.T.P failing on your project site can mean the R.I.P. (rest in peace) for your phase1 and all the following project phases…

Keep the part of the project for testing “unkown unknowns” at about 15% of the total project and you will be fine…


This guy is selling the Basalt rebar, and it has been used in place of steel rebar in reinforced cement hulls. The FRTP Basalt rebar is what he is selling. If someone has found a means to modify the inherent shape, reducing the inherent stress created by bending it, then we can have a curved hull that does not want to be a straight wall. In other words, by modifying the shape of the rebar with heat, the hull reinforcement is not trying to pull the hull apart.

Meanwhile, when steel corrodes, and it IS a matter of ‘when’ not if, it will cause damage, eventually leading to failure.

His methodology description is crude and useless, but the pdf I posted earlier deals with the type of modification I am talking about. I would not be afraid to use heat, to relieve the stress, or modify the shape, but burning the polymer out and rewetting with epoxy is extreme, in my honest opinion.

The significance of a form of rebar that cannot corrode, surely hasn’t been lost on you…?

In a ferrocement hull, the problem is the inability to examine the rebar, which is what leads to the rapid devaluation of ferrocement hulls. With Basalt rebar, that becomes a moot point and there can be a visual record of the construction, to verify the elimination of steel, thus maintaining the value of the hull, for any future resale.

If one made 2 identical hulls, one with steel rebar, the other with Basalt, and documented the whole process, the differences would include a decrease in mass, and a decrease in the hours to make the Basalt rebar hull, along with the fact that the steel will corrode and the Basalt cannot.

The steel one may cost less, materials-wise, but the difference in weight and time could well mean that the Basalt rebar hull cost the same to build. Handling steel rebar is tedious and dangerous, due to the sheer weight and wire-tying. Basalt rebar is typically zip-tied, a much safer and quicker process and the plastic tails are far safer to deal with. However, the FRTP CAN be glued together, making zip-ties and wire-ties unnecessary, and it becomes a game of applying glue, aligning, and clamping until cured, come back, colect clamps and move on.

I learned to hate steel rebar, building concrete slabs. I’ve used rebar from 1/4" on up to 3", between house slabs and slabs for a concrete dam. I am very familiar with the process and the inherent danger of using steel. Not only the mass, but the conductivity and even the toxicity of the coatings. Throw an extension cord across steel and you’re tempting fate. Basalt rebar is non-conductive. There’s another layer of safety, beyond mere mass, in handling.

I’m not the preacher, I’m the new convert in the choir, and I’ve never used it, but I will, now I know it exists.








This is the pdf I linked in the first post, converted to images.

Geopolymer Concrete, the perfect seasteading material

Lost on Ellmer? Heh, you can be sure it’s been lost. He wants investors, people with more money than brains, to throw money at him. He’s not after actual practical seasteads.


I’ve just shown that the switch is cost effective. In comparing a ferrocement hull to typical wood and fiberglass construction, the weight savings began at 25 ft long hulls and up. Basalt FRTP runs 0.28kilo vs 1kilo for the same size steel rebar, but costs twice as much, length for length. By saving that 72% weight, you can have a significantly lighter hull, with significant savings possible in time, possibly matching the cost, on otherwise identical hulls.

A typical ferrocement hull has an expected service life of 25-50 years, mostly due to spalling and corrosion of the steel rebar and the wire-ties that hold it together, during construction. I’ve also eliminated those wire ties, eliminating failure points. Until learning of the Basalt FRTP, the main advantage of steel was the ability to shape it, without the added stress of FRP rebar acting as a spring. I’ve eliminated that advantage.

Now it’s down to cost, but at the same time, since the FRTP has better tensile strength, and is corrosion proof, the hull can be redesigned for more weight savings, since the majority of the cement is to slow the rate of corrosion, so, now we have further materials cost reduction for a lighter hull of the same strength and more service-life.

FRTP just put reinforced cement hulls back into the realm of highly practical, and possibly cheaper than fiberglass, requiring lower necessary skill at constructing.

Line it up, glue and clamp. use an IR heat source to de-stress, before adding mesh, plaster and let it set up.

In the end, you have a sturdier, lighter, more durable hull. Given the exact same specs, you need less flotation foam, meaning you also have an increased capacity. Maybe it saves 30% of that foam, but that’s a significant amount of space, in a 25 ft hull.

(Wilfried Ellmer) #12

@JL_Frusha, please contact me on private message…

(Wilfried Ellmer) #13

@KatOnTri, to get a less confused image about me check here


No thanks, i can read what you have said here, that you lie and claim have built far beyond what is in the cgi pictures you steal without credit from others.

(Wilfried Ellmer) #15

@KatOnTri - stop comitting the crime of calumny against me on this public forum inmediatly - this is “flagged for moderation” from Ken…you have done sufficient to deteriorate forum quality…this is the “go no further line”.


@Ellmer , stop saying i am decieving about you. Please read post from this month before now where you claim to have build places “beyond” the pics you posted. One pic you posted on Marinea thread is not floating, it is from a high-rise building someone else built. And please note that you do not give any credit to the people who did the cgi pics you posted on this website or on your own websites. Therefore, i did not decieve, i did not commit calumny against you.


email I just got, on other Basalt products and their uses…

Tesla bumpers…! Who knew?


You shouldn’t post urls to pages linked to your accounts anywhere. Instead, find the site’s general public urls to hand out.


It’s a view-online advertisement page. Doesn’t link to my account at all. I also wanted it to include the active links to the company and more info on the products, not just be a snapshot. I don’t think anyone here would be able to view my email, even if I posted a direct url that I could open.


Gotcha, you do not believe “e26c37a8-88bd-4086-ac78-ec20e9f15bc1&c=f2c9c200-29bb-11e5-a035-d4ae529a8786&ch=f2cd6b80-29bb-11e5-a035-d4ae529a8786” is a tracking url to you at all.


And phrogjlf@yahoo.com isn’t you either, gotcha.