Home made ballistic concrete

I would have to agree.
The one thing that could be added to concrete that was easy to apply, was also one of the cheapest:
Nylon fiber.
So far I have only tested nylon fiber. My fiberglass samples are still curing. I am expecting them to also do very well.

These are just small scale test I don't think anyone should make a wall 1.75 inches thick. Sure I could make a 3 inch thick sample then I would have to shoot it probably 6 to 8 times to get a control same to fail. It would just waste ammo and concrete.
Neither of which are free.

I found my reduced air samples failed spectacularly. I had 2 samples, 1 I vibrated a lot the air out of the mix, the second I pulled a high vacuum to remove most of the small bubbles. Both were totally wrecked after 2 shots. A typical control normally takes 3 shots

If some one was going to make a new build I would say use ICF and pour the cheap concrete as thick as you can afford and put in rebar like it's going out of style.

Thank you, I suspected soap might work. It's used to make AirCrete.
It will be cheaper than Styrofoam beads for sure.

I bought a concrete surface hardness rebound hammer tester. Aka the Schmidt hammer.

It appears that my home grown 1:1:2 mix is as hard as the store bought 5,000psi mix.
The advantage to home made 1:1:2 mix is its about half the price compared to buying bagged hardware store 5,000psi cement.
But that all depends on how cheap you can get sand and gravel for, could be less or more depending on the cost of locally sourced materials.
For comparison my much weaker 1:3:4 to 1:4:4 sub 3,000psi mix didn't even register on the Schmidt tester. This is commonly what buildings use. Yikes.

Here is 1lb per yard of nylon fiber in unreinforced concrete. These are 12x12 squares 1.75 inchs thick shot with a 22mag rifle. It actually took 6 shots to blow this sample apart usually 3 or 4 shots blows a unaltered concrete and water only sample like this apart.
It took 6 rounds in this picture. The slightly larger crater is actually 2 rounds.
The recommended amount of nylon fiber is actually 4lb to 20lb per yard of concrete. I didn't find this out until after I cast the sample.
All samples are left to set for 30 days.

Here is unaltered 4,000psi concrete reinforced with cheap plastic mesh on the front and back. By cheap I mean its $4 per layer per yard of concrete in a 4 inch wall. Here it is after 5 shots.


Here is the back after 5 shots.


And here it is after 6 shots.

Here is some store bought 4,000psi concrete that I added additional cement to and course aggregate.
This 4,000psi +cement +aggregate mix is nearly identical to my 1:1:2 mix and 5,000psi store bought mix. The 1:1:2 and 5,000psi mix appear to be slightly harder according to the Schmidt hammer.
The harder concrete is more brittle. The impact craters are much smaller on the harder cement but it takes the same number of shots to break the sample.


failed


I have shot a lot more samples than just this.
So far I have found that most additives besides water reducer and super plasticizer don't do anything.
Fiber additives appeared to be the most effective for the money.
And the mesh reinforcement is one of the best.

So eventually looks like I will be testing hardened superplastisized concrete, with fiber additive wrapped in mesh.
I'm curing extra air entrapped concrete too to see if that helps too.

That magnesium cement looks very cool but I am trying to limit this experiment to bulk materials such as cement, sand, gravel and reinforcement such as mesh that can easily and cheaply be obtained locally and additives such as fibers, super plastisizer, fumed silica, maybe fly ash that can potentially be affordably mail ordered.