Posted: 1/21/2004 3:45:40 PM EDT
|
They'll stop most small arms save 50 BMG right? How much do they cost and how many would it take to make a wall 100 feet long, three feet high? Nevermind the mortar. |
|
A concrete block does exactly shit to stop even a 9mm. They bust apart easily. However, if you grout the wall, it is a concrete wall, and that would stop most small arms. You wouls still have weak points at the vertical hoints, however. Your wall would be 3'4", as block are almost all 8x8x16. Your cost per block, is about $10-12 per sq ft installed. Your wall should have 375 blocks in it, give or take a few for breakage and such. |
|
I accidentally put a 5.56 into my Lanen stone house wall once. Made a lead colored stain and a little chip. I live in a bullet proof house! Guys, rebar wouldnt do much to stop bullets, it doesnt cover enough area. Its good if you are worried about bombs or earthquakes, but good luck finding people in FL who understnad reinforced masonry. Its hard enough finding them out here where the codes require it! |
|
Combat_Jack- You sound like you know a bit about the application of CMU, but not very much about the structural aspects of designing a CMU wall. EVERY CMU wall should have grouted cells and vertical reinforcement (rebar). The only variable is the number of bars per cell, and the spacing of the fill cells. For example, on the project I just came off of (yes, here in Florida) the exterior walls had every cell filled, and 2 #5s (if I remember correctly) per cell. The science behind what makes buildings stand up is very interesting, with each material using it's relative strengths to make up the structure. Concrete, or "cinder", blocks are first and foremost concrete. Concrete has a high resistance to compression, but very little resistance to shear or tension. Rebar has a high resistance to tension. The rough surface of the rebar grabs onto the grout (which is basically concrete without aggregate) and that in turn bonds to the concrete of the block. |
|
Sand is iffy, but probably better than nothing. What you have to understand is that the grout in a CMU wall effectively bonds to the block itelf. The entire wall then acts like a solid concrete wall. If you fill the cells with sand, you won't have that bond. I would imagine that the block could/would still crack, even though it and the sand would likely still stop most bullets. The problem is you may only be good for one shot in any particular location, whereas a properly constructed CMU wall with every cell filled would sustain multiple hits in the same spot. |
|
Norman, I know how it works. I am saying that rebar is useless against rifle rounds. If I were to deal with a bomb or earthquake, rebar is the only way to go. Also, consider that mortar is useless in large quantities. The thinner it is, the stronger it is also. We put grout and rebar in all structural walls. Every other course is a bond beam, usually. Verts in most or all of the cells. BTW, I didn't mean to insult you, but it has been our experience that people from back east rarely understand reinforced masonry. Normally the foreman can make sure everything goes together, but we have some walls that have to come down from time to time. Inspectors will drill them and make us take them down for air pockets in the grout, or somebody leaves some steel out. |
|
I've shot cinder blocks with 9mm, 44 mag, .308, .223, and various other rifle rounds. A stand-alone cinder block won't stop 9mm FMJ and JHP shatters the block but usually can be found laying in front of the block. Needless to say, all other calibers went through the block completely. Edit: Same result with 12GA buck and slug.... duh. |
|
Quoted: Sand is iffy, but probably better than nothing. What you have to understand is that the grout in a CMU wall effectively bonds to the block itelf. The entire wall then acts like a solid concrete wall. If you fill the cells with sand, you won't have that bond. I would imagine that the block could/would still crack, even though it and the sand would likely still stop most bullets. The problem is you may only be good for one shot in any particular location, whereas a properly constructed CMU wall with every cell filled would sustain multiple hits in the same spot. He is right about sand. It will pour through a gap in the wall and everything above it is useless. If you grout it (you can make a wall without grout, but dont put too much weight on it) you can shoot the face off of the block and the grout will stop the rounds a while longer, and a face shell is an easy repair to make. |
|
Quoted: Norman, I know how it works. I am saying that rebar is useless against rifle rounds. If I were to deal with a bomb or earthquake, rebar is the only way to go. Also, consider that mortar is useless in large quantities. The thinner it is, the stronger it is also. We put grout and rebar in all structural walls. Every other course is a bond beam, usually. Verts in most or all of the cells. BTW, I didn't mean to insult you, but it has been our experience that people from back east rarely understand reinforced masonry. Normally the foreman can make sure everything goes together, but we have some walls that have to come down from time to time. Inspectors will drill them and make us take them down for air pockets in the grout, or somebody leaves some steel out. I was just talking about your "but good luck finding people in FL who understnad reinforced masonry" comment. As if there is any other kind. I suppose if you're building a masonry non-loadbearing wall you could get away with that, but even our non-loadbearing walls were filled every 3rd cell (I think, maybe eveyr 4th) and and capped off with tie beams. |
|
I guess I question you more, I am a civil engineer and have dealt with concrete design and construction for 16+ years,, The cinder blocks for buildings are far from reinforced concrete. Blocks with or without sand filler will be broken apart very quickly with small arms fire. Now, walls that are constructed of concrete batched at a decent water-cement ratio and have reinforcing steel in it can weather much better. The strength of the concrete (mix design) and rebar placement will last much longer. I am guessing a 6 to 8" thick wall with some earth placed in front of it would do nicely for small arms protection. 100' x 3' x 6" = about 6 yds of concrete. 6 x $500/yd = $3K for a comercially placed wall with steel in it. Go with the steel and Class A concrete. (Not the cinder block wall.) It will outlast much more GL steady |
|
Quoted: Hey CJ, are you a hoddy or a bricklayer? I did my hod carrying in Nevada. Lots of block. Part time hoddy, part time expediter, part time office staff. I was raised with masonry, so I know a bit. I wont pretend to be an expert though. Norman, sorry about that. Thats a little on the light side compared to what we put in a wall, and I hadnt thought of the hurricanes and such that you would reinforce a wall with. Around here we tend to think of reinforced masonry as a western thing, because of the earthquakes. Captainpooby, for your purposes you are best off forming a concrete wall. It doesnt have the gaps of a CMU wall, and it requires basically no special tools or skills. Cheaper too, I am sure. CMU is expensive stuff. EDIT: Read what Steady has to say. A concrete wall would be cheaper, since you have to pour a foundation for CMU anyway, and then the CMU runs at least $3k. |
|
4 blocks high X 100'=300 blocks. This gives you a 32" high wall.5 blocks gives you 40" high. If you are going for a shooting range wall you will probably be ok with concrete blocks filled with "block fill" from your local concrete plant. You will be shooting parallel to the blocks and will have an extreme angle of deflection if you do contact the wall. Your backstop at the end can be cross ties fronted with several layers of old tires. Here in Tennessee, 8"concrete or "cinder" blocks sell for about $1. There are block layers that will lay them for about $1 each. Add the price of your mortar and sand. Rebar wouldn't hurt to tie the blocks to the footing you would need to support the wall. I have been toying with the idea of a block walled range dug 8' deep and topped with ties. It would cost me about $12,000 for a 50 yard range, 7 feet wide and 7' tall. Good luck. |
|
Quoted: Your cost per block, is about $10-12 per sq ft installed. Your wall should have 375 blocks in it, give or take a few for breakage and such. Man who in their right mind would pay that? The going rate for block work here in jersey is $1.10 per block cost and about $3.50 labor, it comes out to roughly 5.00 per block labor and material. And yes I know that the 8" X 16" block is not a square foot, it is 128 sq inches compared to 144" per sq foot. But I believe they quote it by the block, not the sq foot. OK now that we have that straightened out, use earth, bring in a few large dump loads and pack it to desired height and width plus length. cheap and it will stop a 50 BMG round no problem. |
|
in one of my dad's gun magazines they tested a new bolt action .50bmg rifle it was blowing wight through solid concrete blocks. Pretty cool. While I haven't personally shot any caliber at any form of conrete, I have seen pics of blocks that have been shot with common handgun calibers and single shots were able to at the very least break the front side (these were hollow blocks) and often broke the back side as well |
|
Forgot to mention: There is an effect when munitions hit a wall, of knocking material off on the opposite side. This is called spalling, and when dealing with tank guns and the like, can be deadly. I dont know how serious a concern it would be in your situation though. |
|
Quoted: This is for defensive purposes. I was thinking about running a 3 foot high perimeter around the base of my trailer for a place to "go to". You might want to think about burying a steel cluvert or a basement or cellar type of setup, if the terrain allows it. We shot up a trailer at the Great Southern Freedom Shoot and it wasn't pretty. A friend of mine burried a large ceptic tank with a door cut out to make a storm shelter. I dont think a block wall is what you need. |
|
I just want a place to duck if I need to. I dont expect any incoming fire if they cant see me but if a shot is fired I would like some protection. I dont want to hide behind 2x4s. I think blocks with sand will do what I want if can afford it. Thanks you guys. I may build a hurricane shelter. |
|
Find yourself some used steel road plates. They are used to cover trenches in the middle of roads. Have them cut to your desired height plus some extra to bury in the dirt or a concrete footer. You could have slots cut in it so you can return fire. You would have to pay someone to weld it together. It will stop anything up to .50 cal and might stop it too. never tested it fpr a 50. |
|
About 8 years agoa friend did this experiment already- a 4' high by 8' long 8" block wall, left half filled with concrete. The right half (emty) positively disintegrated under fire- even handguns broke blocks. AK and 12ga slug hits were spectacular! Dust and flying pieces. The filled side was shockingly better. Even .300 winmag only cratered it. It looked really bad, and cracked but stayed together. We did find every void that the concrete missed, though! The difference between the to sides was amazing. There was no rebar, either. That may have been even better. |
|
Bobbyjack, I finally have proof that you guys are listening to me! I worked the summers I turned 14, 15 and 16 for my family company. Last summer I graduated and worked right through to December, and now I am back at school. I dont know about steel plates. Our backstop is at a 45 degree angle, and the SP .30/06s almost go through at 100 yards. Dead on with M2 ball, at 35 yards, youre hurting. I still vote for poured condrete. Somehow I found time to do a little of that too, and its not too hard. |
|
CJ we have a lot of younger members here Eladnflow is 15,SW is 15,tivolia410 is 15,leelaw is 20,lokt is 20,and some of just remember when someone tells us something about them(adds to the validity of there posts). For instance Old-painless said in another post hes has been using WD-40 for fifty years to clean his guns(OP is 57) that means he has been cleaning guns with WD-40 since the age of seven! Does this mean that the person posting doesn't know what they are talking about just because they haven't been around long enough to actually experience it? No because with GOOGLE many opinions can be made by reading about something with out really doing it! Bob [:D] |
|
Quoted: jrzy, my company gets $10/ft2 for CMU, and we are on the low end as far as union companies go, because a company our size gets a good deal on materials. We do almost all commercial work. Some VERY high end residential. I can understand that, that was the high end of high dollar work. I use subs from time to time on some projects and thats the going rate and we are high in jersey. Union scale is a whole nother ball game. |
|
I dont ever "expect to draw fire".[:D] I was just thinking that I live a trailer and in any worst case scenario it offers little, if any, protection from bullets. The trailer could use a skirt anyway and I thought I would like it to be usefull as well as aesthetic. 100yds.[;)] |
|
Just my .02 Nothing beats reinforced conc. my second choice would be a double wall of grouted CMU's with a heavy gauge (and narrowly spaced) WWM sandwiched (grouted and tied) in between. third would be a double wall of half thickness grouted CMU's with a heavy gauge (and narrowly spaced) WWM sandwiched as above. |
|
I know what stops most if not all small arms and alot of people already have it in their gardens. I have been in a couple shoot houses made of the stuff. stops everything we use. Check on the constuction of a shoot house. I bet if you GOOGLED it you could gleam alot. How about a 3 ft tall wall of railroad tyes. You can get them at most box stores. If you stacked and drill holes every 18" and installed rebar at least a few feet in the ground for every course. I wonder how stable it would be ? |
|
Quoted: CJ we have a lot of younger members here Eladnflow is 15,SW is 15,tivolia410 is 15,leelaw is 20,lokt is 20,and some of just remember when someone tells us something about them(adds to the validity of there posts). For instance Old-painless said in another post hes has been using WD-40 for fifty years to clean his guns(OP is 57) that means he has been cleaning guns with WD-40 since the age of seven! Does this mean that the person posting doesn't know what they are talking about just because they haven't been around long enough to actually experience it? No because with GOOGLE many opinions can be made by reading about something with out really doing it! Bob [:D] Hey EladEflow is now 17 [:P] Wow I feel famous now, someone brought me up in a thread... spelled the board name wrong but that doesn't matter![BD] |
|
Quoted: This is for defensive purposes. I was thinking about running a 3 foot high perimeter around the base of my trailer for a place to "go to". Huh? Two things will happen. They'll nuke you from the air, it's the only way to be sure and your defensive wall will keep all your trailer debris and the cinder version of you from blowing into your neighbor's yard. |
|
Quoted: I know what stops most if not all small arms and alot of people already have it in their gardens. I have been in a couple shoot houses made of the stuff. stops everything we use. Check on the constuction of a shoot house. I bet if you GOOGLED it you could gleam alot. How about a 3 ft tall wall of railroad tyes. You can get them at most box stores. If you stacked and drill holes every 18" and installed rebar at least a few feet in the ground for every course. I wonder how stable it would be ? I think you may be on the right "track" with that idea. Its not permanent either. Anyone know how much they cost? How big are they? |
| Why not just dig a footing around the trailer, add some #5 bar in two runs supported by some chairs, float off level and then use some ICF's for the wall. Insulated Concrete Forms are so simple to assemble a child could do it, in fact I've instructed some of my crews 19 yr olds. Add some vertical dowels in the footing after you figure the layout of the wall lines and use some bar in the form of a "J" to act as a "vert". Just "soap" it in when the 'crete is wet. Install forms over the verts and run one "hor" (Horizontal, not the other kind) at 1.5 ft. and pour off the truck through some "knockouts" at the top of the wall. Simple:)The ICF's let the 'crete cure real slow and hard! Heck, use some 5K crete w/ plastic in it and you've got one hell of a wall. |
|
12"-3 core blocks that are filled solid with mortar will stop all small arm fire. The "eared" blocks are known as regular (collar) block. "Flat" ended block are jamb blocks. A solid block was with an additional 4-6" solid rock faced block veneer, will stop a .50 no problem. I have been a bricklayer for over 15 years. |
|
Quoted: Would be pretty simple (and interesting) to make up a few test "walls" out of 4 to 6 cinder blocks, rebar, and redi-mix. Take out to favorite shooting area and blast with common rifle/pistol rounds. Take lots of pic's and report back here with results. LMAO those would weigh a good 200 lb ea. |
|
Quoted: 12"-3 core blocks that are filled solid with mortar will stop all small arm fire. Even the best stuff will get broken down with repeated hits. The MOUT manual breaks it down by calibre and length of burst. Hey, cp is obviously planning worst case here. [^] The "eared" blocks are known as regular (collar) block. "Flat" ended block are jamb blocks. Dunno if that was in ref to my "eco block" joke above but in case it was, I was talking about the large (5'X3'X3') stackable conc blocks usually used for breakwaters, jetties, and retaining walls. A Google search shows that "ecology block" may be just a NW WA term for them. I couldn't turn up any pics. Another option is defensive landscaping. [img]http://www.terraforce.com/jpg/step.jpg[/img] |