Seasteading Cement is something that Arktide has been working on for over half a year now. We took inspiration from UHPC or Ultra High Performance Concrete in determining which materials to use in its creation, although it could also accurately be placed into the Industrial Mortar family of materials. After starting with three different UHPC formulas, we altered the formulas after each series of trials and also took into account the most cost effective materials we had available to us at the time.
We are still in the early stages of testing this material, but already at this stage we can tell some of the properties this final material will have:
None of our Seasteading Cement samples cracked during their curing phase. Often if concrete is not kept properly moisturized during curing it will crack itself even in this early stage, although staying wet in the ocean likely won’t be a major concern when we reach our deep ocean construction phase.
- 11,000psi Compressive Strength
More than double normal concrete. Later versions of our material will reach as high as 20,000psi.
Allowing us to make very thin pieces but still retain high strength.
- Greater than 1,160psi Flexural Strength
During our initial testing phase, two of our test blocks were unable to be broken and the machines had to shut off at only 1,160psi because it was unsafe to go higher. Normal concrete has between 400psi and 700psi flexural strength, but we believe we can easily reach 1,400psi in later testing, this means that the bending motions of waves on the structure would not cause it to crack.
Leakage will be much lower than normal concrete because of denser packed materials. This densely packed structure of the material is also what gives it it’s longevity and strength.
While concrete typically weighs about 2,450 kilograms per cubic meter, our Seasteading Cement only weighed 2,280 kilograms per cubic meter, a significant weight reduction despite it being stronger in all regards.
- Made of Recycled Materials
At a later date we will disclose the formula to make Seasteading Cement, but for now we can say that many of the primary materials used in its production are recycled materials, making this a very green and environmentally friendly construction material. We believe that after it has proven itself at sea, it could be used in land based construction as well, and may play a role in improving the future of land based architecture.
This point goes hand in hand with the last one. Here in the Philippines where Mitchell Suchner and Andy DeOcampo have been heavily involved with creating this material, we have found sources for our supplies that allow us to get the price of our seasteading cement down low enough that it nearly matches normal concrete prices in the United States. This is one of the biggest breakthroughs we have had during its creation process, since UHPC on which this formula is based, is known for being far more expensive than ordinary concrete, with some suppliers asking for prices 4x to 10x normal concrete price. Seasteading Cement will only cost 10% to 80% more than normal concrete.
Another factor that sets Seasteading Cement apart from UHPC is the removal of any element from the formula that could react with salt water. There are no steel fibers, or other chemicals in the formula that will degrade performance significantly over time.
The final completely untested property of Seasteading Cement will be its ability to self heal in salt water. Our plan is to introduce a new material into our formula at a later stage that will allow it to be used like rebar when making seacrete. By making Seasteading Cement slightly electrically conductive, a small current could be applied, so that any cracks that might form in the structure would be filled in with seacrete, this scar tissue would be immediately solid and would most form in areas where damage has occurred on the structure. This will allow ArkPads to repair themselves after storms or collisions with boats automatically, and without any repair team needing to be called.
In later tests we will attempt to prove our hypothesis that Seasteading Cement will last at least 100 years in the corrosive environment of the open ocean. In some tests carried out on UHPC samples in Canada, blocks of the material were placed on a beach and exposed to hundreds of freeze thaw cycles in the cold salt water environment. Despite the considerably damaging circumstances, even after 25 years the blocks were almost entirely undamaged, similar testing can later take place with blocks of Seasteading Cement.