Concrete Reinforcing

dont be such a galute! use ballast and gauged steel mesh

The concrete can be pulverized to make aggregate for new concrete, but wire rope can only be used in prestressed or post tensioned concrete when it has anchors at the ends. Concrete will only bond to the outside layer of wires and will not develop the interior wires, hence the anchorages.

I've used 1.5' x 4' chunks of concrete to take up space in footings reducing the concrete required for the pour, yep. This is going to sound hokey but we've tied wire rope and old bed springs and even a few auto chassis once.

But tie em and maybe weld em, what's this for?

If you bury junk in your concrete, that's what you get - junk. (and failure)

Junk cannot be evaluated as anything else but junk.

Do it right, do it once

We did this once and we did it right with junk...if the right steel is junk then the right junk was used right...

You say 'upper mid-west'? Must be somewhere in the hills of Kentucky. Your methods are not just hokey, they are lacking of any engineering logic at all.

The OP hasn't specified any requirements, the slabs I described have withstood the abuses of class 8 trucks for 20 years for junk that's okay.

Don't jump to conclusion so quick, scrap 4130 and A36 serves as well as fresh bar

Besides there's more in them thar hills and though I am not from there bad mouthing a Kentuckian...shows your short on learning.

I agree. I've done a number of pads at my place, for friends and family. We've thrown boulders, wire cages, metal shelfs from ware-houses, shovel blades, anything available to add strength. The only items I wouldn't throw in would be anything organic materials in like wood, or a body. I guess one or two bodies is OK once in a while. Being from Philly you have to do what you have to do you know.

The reason that "other stuff" is dumped into a concrete pour is most often that the quantity ordered was not enough to fill the form. If all that you are doing is creating a base for a flag pole, and you ordered 1 cu. yd. of concrete to fill the hole that you carefully measured at 3'X3'X3' and you didn't get enough ready mix to fill the form, is that concrete is batched by weight per cu. yd..

If the materials used were heavier than needed, you will be left with a batch of concrete that weighed as much as a cu. yd. is supposed to, but the actual volume will be reduced. That is why you have a rep from the batch plant stop by and order the concrete for you. He knows just what the "present multiplier" is to use when ordering said mix, so that you do not have to dump "other stuff" into the form to fill it , or even worse, pay for a small call back load.

TMF

Since I've run several batch concrete plants my self and have done this on my own I have a pretty good idea of how much concrete we needed. We stuck the extra suff in it to make sure it would be in there an extra long time. The pad is a 12' x 20'x 1'. I put it in a my dad's place. It's been there for 25 yrs now. We put bolders that where laying around and some metal selves that where left over at a ware house he ran. It was used as an parking area for his RV. I feel sorry for the sucker who wants to remove it.

By the way who in there right mind would make a flag pole pad 3' x 3' x 3', talk about over engineering. Besides most places won't batch just one yard it's not worth their time. They'll make you take at least 2 1/2 to 3 yards or they'll charge you an arm and a leg.

Well, actually "Mr. Concrete man",

I have been paid to follow the plans, "DON'T YOU SEE" and when the structural Engineer determined that a 50' tall flag pole required 1 cubic yard of concrete poured into a form that measures 3'X3'X3' to provide a substantial base for the flag pole I placed at a local fire station, that I supervised the construction there of, I choose to follow the plans and specifications. Otherwise, I become responsible for said flag pole blowing over in high wind conditions and become liable for injury and damages accordingly. "DON'T YOU KNOW"!

Where were these batch plants located? Were they any where near "Hogs Nuts, Ky.

I DOUBT SERIOUSLY THAT YOU EVER RAN A BATCH PLANT, as is evidenced by your response, Maybe you spent a little too much of your life removing the material that builds up inside of the mixing drums, though.

TMF

I see a person with no imagination. You should learn to think outside the box. Boy that's one big project putting in a flag pole. You actually needed someone else's design plans to put one up. Did you break a sweat standing there pouring over your design for a flag pole base?

I live in PA (Pennsylvania) near Philadelphia. I guess your a little limited on geography being a "math geek". Being a "math geek" shouldn't you at least know that Philadelphia PA is in Pennsylvania not Kentucky?

It's obvious you've never dealt with a concrete plant. If you didn't know that they would charge you extra for wasting a truck with one yard in it. Must intelligent plant operators will not ship material out with at least 2.5 to 4 yards to cover their behinds. It's just not economical unless the fool buying it really wanted it then I would charge them extra.

I haven't had to worry about jack-hammering a drum in a while maybe 20 years, but at least I was smart enough to know the job of each and everyone in my crew. I learned to use my head and heads not just a book or a computer to think. How about you "math geek"? Have you ever gotten your hands dirty? Actually felt what the material your designing with. Have you seen the material in action and worked with it? I doubt it to busy playing computer games or doing math calculations.

All this is getting very bitchy, you should all live so long to see how the concrete performs in the long term.

I'll put my money on the correctly designed and executed work anytime.

There is no good going to college, getting qualifications and accumulating years of experience for some hick to tell you that old bedsprings, shovels and odd boulders are as good as the real thing.

Alonzo,

I raise my glass and make a toast to you for such an eloquent and straight forward blogger.......

you cut to the chase my good man, cutting through all the Bullsh*t flying around here.....

and I might add that I couldn't have said it any better myself!!!

Here here here!!!!

A boring machine I set needed a 7' depth 22' long and 12' wide base, using .875 and 1.25 re-bar, I don't recall the mix but was to specification, the soil was sand with clay at about 3-4' depth.

We can and do well when is needed but for pad to put the barbie on we don't fret; we may use the old grill for reinforcement

You can't just through anything non-organic into concrete and say it would add strength. Being a math geek engineer, the only way to say it adds strength is to quantify the strength, and that can't be done. The whole reason for putting steel into concrete is to increase concrete's ability to resist tension. Since concrete has little to no tensile strength (might as well be none), the only way that the steel can resist the tensile forces is through the bond between the concrete and the rebar. Junk in the concrete means no bond and therefore no strength. However, if a bond can be proven and quantified then the strength can be determined. Side note: A running gag in our office when we read the article on the bamboo reinforcement was that we could design a slab using red licorice, but it would not resist the loads we have to place on it. We thought bamboo reinforcement was a little weird, but a bond strength and a tensile strength can be quantified; therefore it will work as long as the capacity of the slab and reinforcement is not overstressed by the load on the slab.

How many years of field work to you have? Sometimes things in the field work a whole lot different then on paper. I started working in the construction field at the age of 16 digging foots and pouring concrete for basement walls, and have 5 degrees under my belt plus 26 years of experience.

I tell you what I have a pad in my back yard is a 12' by 12' x 8" pad made with a load of hot mix concrete with scape rebar and some scape metal I found at one of the sites I worked at. It's been there 10 years a hot tube used to be on it. I would like to have it removed. Come on over I'll supply the jack-hammer and the beer and watch you try and dismantle it. Bring you're own ear-plugs.

My point is not what works or what doesn't. My point is that you cannot quantify the strength of concrete filled with junk. Yes, being in the field is a lot different then being behind a desk, but strength is still strength. Your slab may have been strong enough to work for what it was placed for; that is great. However you can't tell me why, and if whether or not it is close to its maximum load capacity. If someone wanted to take that slab and place something else on it you could tell them that it held a hot tub, but whether it could hold anything larger is a bit of a crap shoot. What if they wanted to put a ham radio antenna on it. If the bottom of the antenna was placed in such a way that it was right above that shovel head you threw in, it might not punch through, but the chances of knowing what was going to happen to that antenna would be really low. The neighbor might suddenly have a very personal interest in ham radio antennas when the tension from the guy wires cause the antenna to punch through the concrete and then it collapses. In all likely hood it could hold something larger, but how much larger. I would not want to take responsibility for it. Yes even calculating a slabs strength is based on many assumptions, but it is a more accurate place to start. I have been in construction since I was a little boy working with my grandfather on his developments. It sounds like you are educated and competent, but I believe you have simply missed my point, and I am sorry for the confusion.

I appreciate your time and your knowledge though you're maybe over thinking it here a bit, your laying it on with a trowel.

If I were to spec a slab for a hot tub my neighbors would think would think I'd that I'd lost it. Because the necessary components of such a pour are of fairly common knowledge. And if I needed a hot tub pad and I wrote a description into the sale documents; whatever the new owner does doesn't reflect on me.

I think I think you're trying to avoid an issue where someone without perspective were to read the remarks herein they maybe thought of as having been ill advised though this is a real stretch.

I suppose I may have led one to believe my use of recycled metal objects placed in concrete was intentionally to by subversive methods disqualify the established codes of safety and structural integrity within the public sphere.

Please excuse me as I assumed others would recognize my descriptions were of slab placements where little to none structural integrity were required.

The description of the scrape metal used in the slab where heavy trucks and equipments traversed over it wasn't attempted without specific attention to tensions required of this type service.

The poster is correct that concrete binding cannot be established for scrap materials generally because the equations are specific to material, however with proper judgement and thorough experience this maybe overcome.

Bwire

Don't apologize it's a sign of weakness (Agent Gibbs NCIS).

I have no problem doing home projects with "used" material. I tell you a secrete it's called recycling.

That isn't very nice, if it wasn't for some of those Kentucky folks and their sharp shooting muskets/rifles you might still be speaking the kings version of what we call english.

TMF

I've seen wire rope used in pre-cast concrete i.e. piers some pipes.

I've never heard of crush concrete as an admixture. Fly ash yes, chemical admixtures yes, but not crushed concrete. What benefit would it give? I have seen crushed concrete used as an aggregate or sand replacement (private use only), and as a sub-base in construction. It's not recommended because of the high wash percentage. We use strictly clean stone less then 1.0% wash for all of our structural and flat work. Anything dirtier then that will reduce the strength of the finished product and cause major problems.

Crushed concrete can be used as aggregate, but the compressive strength of the new concrete is only as strong as the crushed concrete used for the aggregate. In other words if the concrete crushed and used for aggregate is 3000psi the new concrete strength cannot be more than 3000psi. As far as wire rope, because you cannot get proper adhesion between the concrete and the wire rope (and thus development length is considerably longer) it is only used as a supplement to deformed rebar in pre stressed or post tensioned applications.

You also have to watch-out for the -200 mesh. If your wash is to high your strength will go down. Plus the type of admixtures and cement used will affect strength.

A friend gave me a book recently that was devoted soley to using bamboo as concrete reinforcing. All the strength data, engineering design, etc. was given. Amazingly, the stuff is pretty darned tough!

So, my answer to your question is: "Sure; why not?"

Yes you can use wire rope, I have used it to reinforce large garages and shops. We got all our rope free from a steel mill from their overhead cranes. The first thing you must do is burn off all the old oil and grease. When laying it, lay the wire the same way as you would rebar tying the overlaps together and lifting it up as you pour. I live on land that is clay and is constantly shifting with the water contant of the soil. We have had excellant results with the wire rope over the years. If you do get a crack it takes a lot longer to rust out wire rope compared to rebar or wire mesh.

Good Luck and happy pouring

Thank you all for your comments. I'm trying to find materials that can be recycled for use as aggregates in concrete. Clam and oyster shells and cinders have been used as aggregates. Can you think of anything else that might be used?

The meat processing industries have a surplus of bones...and teeth.

Depleted uranium encapsulated in glass

Concrete manual: based on the 2003 IBC and ACI 318-02

The purpose of the OP was to obtain general feedback, not any specific application. I should add that no one should substitute untried scrap materials for tried and true concrete design for projects that were engineered for strength and durability, like a dam or bridge foundation. Any possible application would only be for a DIYer who wants a cheap and dirty slab that will never see extreme stresses imposed. An example project might be a slab for a tool or garden shed; nothing that involves critical loads. Sorry if I misled anyone.

I think you should get a copy of Building Code Requirements for Structural Concrete ( ACI-318-02 or latest edition) and read carefully Chapter 3. You will find why you can`t use old recicle concrete pulverized as coarse agregate. This also applies to organic materials, as oyster shells.

I once saw a longbow made of prestressed concrete!!!
It was done to demonstate the properties of the material, it fine pre-tensioned had steel cables cast into it.
It looked ugly as sin, but it worked!
Del

Clemson U is somewhat famous in the US for building sleek, concrete canoes and winning races!

BYU does the same thing every year. It's a very popular project, and shows just some of the cool things you can do with concrete. It is really cool to see how they are made, and just what goes into the design to keep them afloat.

Apparently, they haven't updated their website in a few years, or they have quit the concrete canoe competitions (I haven't heard of one in a few years, and I used to consult with them some . . .), but here's a website that shows their placements in past competitions: Clemson's Concrete Canoes

Note that the 'Cross Section' pictures shows pretensioning of cables.

Hello All, just wanted to share a short story with ya'll:

Some 30 years ago when I was a member of the Student Chapter of ASCE at Hudson Valley Community College located in Troy New York we built a concrete canoe. Okay, now I'm dating myself here, but what the heck, right? Our adviser was Professor George Limbrunner, a brilliant ex-Navy SeaBee and fantastic instructor, had helped us throughout the entire design and construction process of producing that concrete canoe. Back then it was a rarity for any college Civil Engineering students to actually build one, let alone a bunch of kids from a community college.

Although it involved a lot of hard work and testing, especially showing up early on Saturday mornings very hung-over to build it, it was great fun and we got to learn many new things about concrete properties, buoyancy and how to lighten the weight of the concrete using Pearlite. I believe that we had only entered a couple of races that spring, but didn't win anything.

What was important was that we broaden our horizons and knowledge base, but what was equally important was that for those involved in the project had developed close relationships and comradeship, something that is difficult when you attend a Community College and live many miles apart from your fellow classmates.

Honestly, to this day I firmly believe that my involvement in building that concrete canoe eventually made me decide to continue on with my studies and obtain my BS in Civil Engineering and eventually my PE License.

Wire rope is used in prestressed and post tensioned concrete but don't try this at home. Use the services of a Professional Engineer.

Crushed concrete can be recycled in fresh concrete but it's use is usually restricted to less than 5% of aggregate. Higher percentages tend to affect the final strength of the concrete.

I hope that this is helpful.