Ballistic concrete - Page 2

pinballlooking · 05-22-17, 12:54 PM

I am sure you guys have seen this.
Concrete is vey strong in these test.

https://www.youtube.com/watch?v=rTHehy84XJs

oil pan 4 · 05-22-17, 03:01 PM

The cinder block wall would have done better if it were filled in with concrete.

pinballlooking · 05-22-17, 03:11 PM

I thought the same thing and it would have been a closer comparison.
It was funded by ICF CO.

oil pan 4 · 05-22-17, 05:39 PM

Yes the concrete in the ICF is also 6 inches thick.
Ideally you would make a new build with this, put maybe 20lb per yard of rebar in there, fill it with the cheap concrete from the local concrete company, maybe throw a layer of stucco or brick over it.

Incase that isn't an option, that's where my tests come in.

oil pan 4 · 05-23-17, 07:56 PM

Alright I have identified a few more products to sample.
Quickcrete fast setting green label cures to 7,000psi, no fiber reinforcement.
Quickcrete D.O.T. mix, 9,000psi. That is if I can find it.
Fiber additives, nylon and fiberglass, both formulated for concrete.
The fiber additive is on order from ebay.

This way I can test the effect of adding fiber to 4,000psi concrete.
I can will build a pretty large 4,000psi test base.
Numerous 4,000psi controls where I just add water, stir and pour.
4,000psi vacuum, 4,000psi with polymer booster, 4,000psi with steel mesh x1, x2 and x3 layers and now I will be able to do 4,000psi with fiber reinforcement.
Then I can do combination's of tests such as polymer plus vacuum or all of them where I take 4,000psi concrete, add fiber, wet it with polymer booster, vacuum it and pour it with steel mesh.

You might be wondering how much fiber to add for consistency. Well the manufacturer recommended 1lb of fibers to 1 cubic yard of concrete. To break that down to my paver scale it's about 0.01 gram of fiber per cubic inch of concrete or about 2.4 grams per sample, since my samples are about 240 cubic inches.

This way I can place some sort of value to each strength boosting technique.

I am also going to add a new test metric. I am going to core sample my paver size samples. I will try to take a 1.25 inch cylinder core and 1.75 inch cubed sample for crush testing, if there is enough left of the samples to do before and after shooting. The cylinders will be crushed in strike position as if being hit from horizontal and the cubes will be for vertical load.

oil pan 4 · 05-27-17, 07:35 AM

New batch of tests.
So I found some chopped nylon fiber for concrete, bought a pound of it. Figured 2.4 grams is all I would need to add for a paver sized sample.

I was at lows in the fence section looking for some other kind of wire mesh that would be cost effective to add to concrete since the stucco mesh is a little over 50 cents per single layer per square foot. It's still the the most amount of steel mesh for the money.
Sure chicken wire is cheaper by you go down to like 1 ounce of steel per square foot.
I ended up getting 1 inch plastic mesh netting. It's cheap, more like 16 cents per square foot. It's a thermo plastic.

So I made 3 test forms with 4,000 psi concrete.
The first one using the black plastic mesh with mesh in the middle, medium workable concrete.
The second one using 4000psi concrete. Low amount of slump wetted with a 50/50 mix of poly booster and water.
Last I mixed up 4000psi concrete to medium workability added the nylon fiber and put it in the form. This was supposed to be a low slump mix but I accidentally added a little too much water and made it medium, that was the last of my 4000psi mix for now.

oil pan 4 · 05-30-17, 01:00 AM

I did my 24 and 48 hour cure check where I scratch the surface of the concrete.
The sample with the 50/50 mix of poly booster was much harder at 24 hours than any concrete mix using plain water.
But it would cost an additional $150 per yard to mix concrete with a 50/50 mix of poly booster.

oil pan 4 · 06-01-17, 09:01 PM

I had always heard and read that damp concrete will cure much longer and end up much harder than normal construction methods. Where compared to when it's kept wet for 1 to 3 days after its "walk on safe".
But I had never seen numerical values assigned to how long and how much stronger this wet cure method gives, until now.
Turns out the traditional 7 day damp cure and keeping the form wet for 28 days actually doesn't make it any stronger at all, at first.
Concrete is a such a strange beast, this is where things get weird.
But after 28 days the curing that normally pretty much stops continues when you wet cure. So If you can keep the concrete wet for 90 days it will strengthen to 120% of rated.
If you really aren't in a hurry it will cure to 130% at 6 months if you can keep it wet.
But the concrete doesn't stop at 6 months, just the tests I found. So if you could keep it wet for a year it might cure to 140%. The wet cure strength increase was liner after the 2nd month.

oil pan 4 · 06-03-17, 10:44 PM

I tested my first sample against the 22mag rifle.
When I put a standard store bought paver against the 22mag 1 round severely damaged the paver, cracking the paver and spalling the back. Blasting a 3 inch wide chunk 1/4 of an inch thick off the back side. 2nd hit blasted the paver apart.
The 4,000psi concrete paver size sample was made medium workability and was air entrapped.
The first shot damaged the concrete sample a lot like the hardware store paver but with no spalling, but was cracked and had some chipping on the back side. Second shot cracked the sample, still no spalling. The 3rd shot joined the cracks and the sample fell apart when I picked it up.
So adding steel mesh, plastic mesh, or fibers will keep a few cracks from causing a sample to fall apart after a few hits.

oil pan 4 · 06-07-17, 09:46 PM

I tested my 4,000psi concrete mixed with 25% poly strength booster.
It did actually improve the damage resistance. Unlike regular concrete there was no chipping or spalling on the back side of the block after the first shot.
It seems like a pretty small improvement for what it would cost to go full scale. The cost of going full scale would add an additional $75 per yard to the cost of the concrete.

Bottom line, does 25% poly strength booster make your concrete stronger?
It would appear that it does.
Is it cost effective?
Probably not.

05-22-17, 03:11 PM	#13
pinballlooking Super Moderator Join Date: Jun 2013 Location: SC Posts: 2,923 Thanks: 172 Thanked 564 Times in 463 Posts	I thought the same thing and it would have been a closer comparison. It was funded by ICF CO. __________________ Current project Aquaponics system , Passive Solar Greenhouse build To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Solar Install 12.5 Kwh- To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Mini Split installs - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. EV Chevy Volt - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

05-27-17, 07:35 AM	#16
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	New batch of tests. So I found some chopped nylon fiber for concrete, bought a pound of it. Figured 2.4 grams is all I would need to add for a paver sized sample. I was at lows in the fence section looking for some other kind of wire mesh that would be cost effective to add to concrete since the stucco mesh is a little over 50 cents per single layer per square foot. It's still the the most amount of steel mesh for the money. Sure chicken wire is cheaper by you go down to like 1 ounce of steel per square foot. I ended up getting 1 inch plastic mesh netting. It's cheap, more like 16 cents per square foot. It's a thermo plastic. So I made 3 test forms with 4,000 psi concrete. The first one using the black plastic mesh with mesh in the middle, medium workable concrete. The second one using 4000psi concrete. Low amount of slump wetted with a 50/50 mix of poly booster and water. Last I mixed up 4000psi concrete to medium workability added the nylon fiber and put it in the form. This was supposed to be a low slump mix but I accidentally added a little too much water and made it medium, that was the last of my 4000psi mix for now. Last edited by oil pan 4; 05-28-17 at 10:34 PM..

06-03-17, 10:44 PM	#19
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	I tested my first sample against the 22mag rifle. When I put a standard store bought paver against the 22mag 1 round severely damaged the paver, cracking the paver and spalling the back. Blasting a 3 inch wide chunk 1/4 of an inch thick off the back side. 2nd hit blasted the paver apart. The 4,000psi concrete paver size sample was made medium workability and was air entrapped. The first shot damaged the concrete sample a lot like the hardware store paver but with no spalling, but was cracked and had some chipping on the back side. Second shot cracked the sample, still no spalling. The 3rd shot joined the cracks and the sample fell apart when I picked it up. So adding steel mesh, plastic mesh, or fibers will keep a few cracks from causing a sample to fall apart after a few hits. Last edited by oil pan 4; 06-07-17 at 09:51 PM..

05-22-17, 03:01 PM	#12
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	The cinder block wall would have done better if it were filled in with concrete.

05-22-17, 05:39 PM	#14
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	Yes the concrete in the ICF is also 6 inches thick. Ideally you would make a new build with this, put maybe 20lb per yard of rebar in there, fill it with the cheap concrete from the local concrete company, maybe throw a layer of stucco or brick over it. Incase that isn't an option, that's where my tests come in.

05-23-17, 07:56 PM	#15
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	Alright I have identified a few more products to sample. Quickcrete fast setting green label cures to 7,000psi, no fiber reinforcement. Quickcrete D.O.T. mix, 9,000psi. That is if I can find it. Fiber additives, nylon and fiberglass, both formulated for concrete. The fiber additive is on order from ebay. This way I can test the effect of adding fiber to 4,000psi concrete. I can will build a pretty large 4,000psi test base. Numerous 4,000psi controls where I just add water, stir and pour. 4,000psi vacuum, 4,000psi with polymer booster, 4,000psi with steel mesh x1, x2 and x3 layers and now I will be able to do 4,000psi with fiber reinforcement. Then I can do combination's of tests such as polymer plus vacuum or all of them where I take 4,000psi concrete, add fiber, wet it with polymer booster, vacuum it and pour it with steel mesh. You might be wondering how much fiber to add for consistency. Well the manufacturer recommended 1lb of fibers to 1 cubic yard of concrete. To break that down to my paver scale it's about 0.01 gram of fiber per cubic inch of concrete or about 2.4 grams per sample, since my samples are about 240 cubic inches. This way I can place some sort of value to each strength boosting technique. I am also going to add a new test metric. I am going to core sample my paver size samples. I will try to take a 1.25 inch cylinder core and 1.75 inch cubed sample for crush testing, if there is enough left of the samples to do before and after shooting. The cylinders will be crushed in strike position as if being hit from horizontal and the cubes will be for vertical load.

05-30-17, 01:00 AM	#17
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	I did my 24 and 48 hour cure check where I scratch the surface of the concrete. The sample with the 50/50 mix of poly booster was much harder at 24 hours than any concrete mix using plain water. But it would cost an additional $150 per yard to mix concrete with a 50/50 mix of poly booster.

06-01-17, 09:01 PM	#18
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	I had always heard and read that damp concrete will cure much longer and end up much harder than normal construction methods. Where compared to when it's kept wet for 1 to 3 days after its "walk on safe". But I had never seen numerical values assigned to how long and how much stronger this wet cure method gives, until now. Turns out the traditional 7 day damp cure and keeping the form wet for 28 days actually doesn't make it any stronger at all, at first. Concrete is a such a strange beast, this is where things get weird. But after 28 days the curing that normally pretty much stops continues when you wet cure. So If you can keep the concrete wet for 90 days it will strengthen to 120% of rated. If you really aren't in a hurry it will cure to 130% at 6 months if you can keep it wet. But the concrete doesn't stop at 6 months, just the tests I found. So if you could keep it wet for a year it might cure to 140%. The wet cure strength increase was liner after the 2nd month.

06-07-17, 09:46 PM	#20
oil pan 4 Land owner Join Date: Nov 2012 Location: NM Posts: 1,026 Thanks: 12 Thanked 127 Times in 107 Posts	I tested my 4,000psi concrete mixed with 25% poly strength booster. It did actually improve the damage resistance. Unlike regular concrete there was no chipping or spalling on the back side of the block after the first shot. It seems like a pretty small improvement for what it would cost to go full scale. The cost of going full scale would add an additional $75 per yard to the cost of the concrete. Bottom line, does 25% poly strength booster make your concrete stronger? It would appear that it does. Is it cost effective? Probably not.