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Bill H.
In design and analysis we use 150 pounds-per-cubic-foot: pcf. 27 cubic-feet per cubic yard, do the math. That assumes reinforcing steel bars. For cutting the stuff, if you have a bunch of bars and an oxy-acetylene torch, that is quick. If no torch, use a 4 1/2 right angle grinder (or 5″ etc.) with a cut off wheel for steel.
Ricardo
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Replies
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Bill H.
In design and analysis we use 150 pounds-per-cubic-foot: pcf. 27 cubic-feet per cubic yard, do the math. That assumes reinforcing steel bars. For cutting the stuff, if you have a bunch of bars and an oxy-acetylene torch, that is quick. If no torch, use a 4 1/2 right angle grinder (or 5" etc.) with a cut off wheel for steel.
Ricardo
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Bill,
Concrete does weigh a lot. A simple mix of 1 part portland, 2 parts sand, and 4 parts stone (or gravel) will weigh about 140 pounds per cubic foot. The water added to this mixture adds another 10 pounds. Hence 1 cubic foot of concrete is approximately 150 pounds. Since there is 27 cubic feet per yard of concrete, 150 X 27 = 4,050 pounds per yard. ( Even if you don't count the weight of the water due to evaporation, you still wind up with 140 X 27 = 3780)
I left my Construction Master calculator in the shop at work, which can calculate concrete weight very easily. The weights I used for the above formula came from an old Time/Life book titled masonry. If you want, call your local concrete supplier and ask them; I'm sure they can easily give you that information.
As for rebar.....if the concrete is all broken up as you say, good chance there is none; since rebar's primary purpose is to strengthen concrete and minimze cracking. Welded wire mesh is used for the same purpose. Rebar is always used in commercial/industrial settings, but not so in residential; though it normally is found in house foundations. Driveways, sidewalks, and the like normally don't contain rebar, but may contain the wire mesh. Just use bolt cutters to cut through the mesh. As for rebar, you will need an Oxy Acetylene type torch. When you bust through the concrete and the rebar is visible, burn it off.
Hopefully, you won't have any rebar to worry about, but if you do and you must cut it with a torch, remember to position the torch handle so as to minimize flame contact directly with the concrete; concrete "pops" or explodes when heated too much and you can get splattered with minute debris which can burn you. It's not pleasant. Wear leather clothes and goggles when burning.
If you suspect that the entire slab is rebar reinforced (though I doubt it from the description you gave), you should think twice about doing it manually. Hire a friend with a backhoe and let him and his machine rip up and dump the concrete. Backhoes can easily "peel" up the concrete with their buckets, and should there be difficulty in busting the crete, hoes have jackhammer attachments that make it easier. Bobcats can be rented and can do the same thing, but they are much lighter, and sometimes have trouble; plus for the money, an experienced backhoe operator will make quicker work of the job than an inexperienced bobcat operator/renter. A bachoe operator (with the hoe) should cost you somewhere in the neighborhood of $100 to $170. If you know a buddy who owns a backhoe, he may be willing to do it for $50 and some beer; who knows? Anyway, something to consider.
If you do decide to do it manually, make sure you have plenty of help. this is back breaking work.
Good luck.
Davo
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Bill: In addition - safety first - do not fail to wear eye protection when busting up concrete ( or anything for that matter ). When you hit concrete with a hammer small pieces fly off and will definitly injure your ( or bystanders ) eyes.
*Im for the back - hoe . also about the rebar try a sawzall with a metal cuting blade worked great for me. good luck
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Rent a compressor and an air hammer. Use the smallest hammer you can that does the job. You'll be a lot happier for a large project than with an electric jack hammer and the rental cost is not much more.
*Dumpster? Not so sure that is a good idea. The first question I would have is can the Dumpster take the weight. Second, do you pay by the yard or by the pound to get rid if it? At my dump it is $18 a ton and how many tons did you say you have? Consider hiring someone with a dump truck and a backhoe to do this job. Most of these guys have places to take fill material. Sometimes they even make a little at both ends. At least get an estimate and compare it to the cost of renting a jack hammer and dumpster fees. I took out an old concrete driveway once. Beat it up with a sledge. Nasty work. When I was done I had a busted up driveway so I called a guy with a back hoe and dump truck. He had it all out and leveled off for new concrete in a couple of hours. After watching him work I figured out all of my hours of muscle work saved a couple of minutes of back hoe time. Never again.
*$18 a ton? I'm paying $57 a ton for construction debris.
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I would rent a Skid Steer Loader with a Breaker atachment
Concrete weighs about 4000lbs per yard I think.
Facts & Figures
A cubic foot of sand or gravel weighs approx. 100 lb. (45 kg.) Wet
or dry
A cubic foot of 5/8" crushed gravel weighs approx. 95 lb. (43 kg.)
wet or
dry
A cubic foot of concrete weighs approx. 150 lb. (68 kg.) wet or dry
A cubic yard of sand or gravel weighs approx. 2700 lb. (1215 kg)
wet or
dry
A cubic yard of 5/8" crushed gravel weighs approx. 2600 lb. (1170
kg) wet
or dry
A cubic yard of concrete weighs approx. 4050 lb. (1823 kg.) wet or
dry
A cubic yard has a volume of 27 cubic feet. (.76 Cubic Meters)
Area of a circle = Radius (one half of the circle diameter) squared
I had to remove some steps and a walkway to put in a wheel chair lift .I called the dumpster people and to my syrprise it was cheaper to dispose of concrete than regular debris. They recycle concrete now. Call around .I can't remember the exact price . I filled the dumpster it didn't cost to bad. The skid steer will lift it into the dumpster to save your back. Unless you can't get one in there ,its the only way i would do it .With the breaker attachment you will be amazed at how fast it will go .Probably get it done on a half day rental .
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Hello, I could use some help from the pro's. I read this board every day and you guys are great! I have learned a ton just by reading.
O.K. Weekend warrior here. I am going to bust up about 7 yards of concrete,( I will rent a jack hammer for the day), load the dumpster and have it hauled.
Questions:
1) Any idea what a yard of busted up concrete weighs? 1 yard 2000lbs?? 2500lbs??
2) Any tips on how to handle rebar? I don't expect any but you never know. I just use bolt cutters if any wire but that rebar is hard!!
3) can a metal detector tell the difference between rebar and wire??
This is 1950's vintage concrete in a residential development, it is week and cracked and should come up easy, well, easy as concrete goes, my neighbors house had no wire at all in her driveway or front porch.
I would most appreciate any help or suggestions you may have. I have done this kind of work before, and don't mind the bull work. After all it is our home.
If nothing else guys, KEEP TALKING!!! I love this place!
Bill