Acid vs. concrete.

[Cafe1]

Here's the problem:

I have a 30" by 30" square concrete slab (underground pillar) in my yard that is several feet (or more) deep. It used to be the base for an old ham radio antenna tower that neighbors say was 40 or 50 feet high. The concrete base was put in by the former owners who are now deceased. It sticks up about 1 inch above ground level and I want to get rid of it.

I want to either remove the concrete base entirely, or take off the top 4 to

6 inches so it will be below the ground level. I had a guy with a backhoe try to remove it while he was taking out other concrete sidewalk slabs. He said he couldn't get it to budge and said there is no way to know how deep it goes. I watched him try grasping and hitting it with the backhoe scoop, but nothing happened. It wouldn't break up, it wouldn't move, etc.

So, here's one goofy idea I was thinking about. If I made a little ridge around the slab and poured some type of acid on it, would the acid eat away at and/or dissolve the concrete? Anyone ever tried anything like this? Any particular acid I should try if I am crazy enough to do this?

My other idea is to try drilling holes into the side of the pillar, about 6 inches below the top, then trying to hammer an iron wedge into the holes to try to crack the top section off. I saw them doing something like this on a TV show where they were cutting large slabs of marble. I have tried renting a jack hammer in the past to get rid of solid concrete steps and the jack hammer didn't do much because the concrete was so thick. So, I don't thin a jack hammer would do much to this monster.

My last idea is to get someone else with a backhoe and get them to dig a hole around two sides as deep as needed, then tip it over into the hole, and re-fill the hole to bury the sucker. I wanted to get the guy I had there (with the backhoe) to do that, but it was a real struggle trying to communicate with him, so I gave up.

The bottom line is that I really like my acid idea, but I don't know if it would work.

[Ian Stirling]

Yes, this will work. However, it will require an enormous amount of acid. This might not be very expensive, as barrels of conc acid are not very expensive. However, it's not a safe way to do it.

A big jackhammer will take care of it. Combining this with a diamond concrete saw, to slice the top into a grid pattern beforehand may work.

[m Ransley]

Dynamite will be safer, acid will hurt the earth worms

[Joseph Meehan]

That sure brings back a few memories. I had an uncle who loved to build with concrete and I ended up with his home.

A professional strength jack hammer will be able to take a foot or so off without all that much of a problem. I suggest having someone come in and do it, it will likely not cost you more than renting and doing it yourself.

As for my uncle, he left a 4 ft cube solid block of concrete by the back door. While it was handy to drop off a bag a groceries while I unlocked the door, I did want to get rid of it. I tried all kinds of do it yourself ideas. In the end I dug a large hole and with the help of several other college age guys we rolled it into the hole.

Later when I was having a 24'x24' concrete pad removed from the back yard I insisted on a dollar quote. everyone wanted to give me an hourly rate. I am glad I did. That little pad was reinforced with 4" angle iron. It took them forever to break it up and get it out. They lost money, but they did the work.

[wayne]

Concrete saw to put groove in it then a jackhammer! I would also think about adding some soil and making a mound and maybe a planter?

If the tower was that high I would guess the pad is 5' deep or more

You could rent a backhoe and dig the side out if you are handy but if you are going to do that get a backhoe with a hammer on the end and go to town with it!

more fun same cost ;)

Wayne

[Cafe1]

Thanks. I hadn't thought about a "professional strength" jack hammer. Now that I think about it, the one time that I rented a jack hammer in the past, the one I rented was an electric plug-in type because I had no way to transport the bigger one that was available to my house from the rental center.

That's what happened to me when I tried to get rid of concrete back steps, three steps high (same house as where the antenna tower base/pillar is). I tried all kinds of tricks -- drilling holes, sledge hammer, heavy duty chisels, etc. -- then I ended up renting an electric jack hammer. Somehow I thought the steps would be partially hollow or would have cinder blocks in the center, etc. Instead, it was solid concrete and was a nightmare to break up. The best I could do was jack hammer pieces off along any corners or edges. But, eventually I ended up with a concrete ball that I just plain could not break up. So, like you, I dug a hole, rolled it in, and buried it.

[James Nipper]

Frankly, I would get a ham license and put up another nice tower !!

Just kidding............

--James-- K4PYT

[JerryMouse]

[...]

There's bad news.

Like an iceberg, there's more there than you see.

Consider the torque on a fifty foot tower in a modest wind.

The hunk of concrete you see is probably at the intersection of a large "T" - maybe 20x20 feet with the out-riggers a foot square with rebar. You are NOT going to tip this sucker into a nearby hole.

You have a genuine Caddy Shack moment.

[Minnie Bannister]

Probably not that big: I am planning to erect a 60' tower, and the spec. calls for only a 5' x 5' x 6' base (the same even for the 100' model). The manufacturer gives maximum antenna sizes for wind speeds as high as

70mph for the 100' one and 120mph for the 60' one.

AB2OS

JerryMouse wrote:

[Joseph Meehan]

Maybe you should talk to Cafe1 I understand he has just what you need, all you need do is stop by and pick it up. ;-)

[Cafe1]

I like that idea. I had a novice license when I was a kid. Mostly all I remember about it was having to learn Morse Code and some things like, "CQ, CQ" and "QLF" (which sort of stood for, "try sending with your left foot").

[Cafe1]

You might be right. While I don't know if it would be 20x20 feet, it would make sense that there would be some kind of cross-bar setup below ground.

[raven]

You've had a lot of discussion here, but you know, it may be easier to get a few loads of topsoil delivered, and raise the yard the 4-6" you want to see this thing under the dirt to. Dump the dort on, grade to suit and re-sod.

Acid can indeed weaken concrete, but IMO you'd need gobs of it and create quite a mess going this way.

This is a far more reasonable idea and for a little sweat you should be able to do just that.

If you're patient, and sometimes help things along with other tools, there's no reason why the hammer route shouldn't work, but it will be exhausting and eventually you may end up giving up. Concrete demoltion is the sort of thing where it's worthwhile to call in the pros, as they have the tools to make the job easy, and they'll haul away the concrete.

John

[Mary Shafer]

This is probably a silly question, but what about combining the concrete saw with a high-pressure washer?

A friend's driveway was badly eroded by a fellow with a high-pressure washer (although in fairness I have to admit the big oil stain was also removed), so I know that these will remove concrete. It didn't take long to damage the driveway, either, so I assume that taking the concrete apart wouldn't take forever.

Groove it with the saw and then use the washer to widen and deepen the cut, eventually undercutting chunks until it's gone?

This sounds too simple, so I'm sure there are good reasons that it's a bad idea.

Mary

[barry martin]

Cafe1:

C > I have a 30" by 30" square concrete slab (underground pillar) in my yard C > that is several feet (or more) deep. It used to be the base for an old ham

If you jackhammer off the top or roll it into a hole be sure there is enough dirt above so whatever you are planning to put above will have roots. Grass need 6" (I'm guessing).

- ¯ barry.martinþATþthesafebbs.zeppole.com ®

• Iron was discovered because someone smelt it.

[spamfree]

I agree about raising the lawn. That chunk of concrete is probably huge under the ground. OR, just make some sort of planter or build something over it. How about building yourself a brick charcoal grill on top of it?

I live on a farm, and there used to be metal grain storage buildings here. I got these 20 foot circles of concrete, and some of them are raised up to 28" above the ground. I got some cheap fill, ramped the dirt up to them, and now I use them to park my tractors and other pieces of machinery that used to sit in the mud and get buried in weeds. They are real handy.

Removing large chunks of iof concrete is a lot of work, and costly. I've learned to make use of things like that, rather than try to remove them.

[Jagoff Jameson]

Oh goodie, just what we need, another wannabe who doesn't have a clue but HAS TO OPEN THEIR mouth and GUESS. What a brainless dimwit. If all you have is a GUESS you have NOTHING.

[Cafe1]

Thanks. The concrete I have is rock solid and smooth, so I'm not sure that a high-pressure washer would be able to break it up. I have seen concrete where the very top layer can become degraded and scrapes off, but I think that's from when the concrete was first poured and maybe too much water was used when they "floated" the top to smooth it out.

[Cafe1]

I did think about the "raising the lawn" idea, but where it is located would make that a less desirable alternative. I see myself trying a little of this, and a little of that, just out of curiosity as to what will work.

I also plan on keeping an eye out for anyone with a jack hammer doing work in the area to see if I can get him/her to come over and give it a try.

[barry martin]

JJ> > [e-mail] JJ> >Grass need 6" (I'm guessing). JJ> JJ> Oh goodie, just what we need, another wannabe who doesn't have a clue but H S JJ> TO OPEN THEIR mouth and GUESS. What a brainless dimwit. If all you have is

JJ> GUESS you have NOTHING.

One: I admitted to guessing so the OP nor others lurking would know to check for proper information.

Two: My interpretation of your post was you prefer to rant rather than supply the correct information. May I ask, would you kindly educate myself and the others in this newsgroup/conference of the correct depth?

- ¯ barry.martinþATþthesafebbs.zeppole.com ®

• Who is Lo Bat and why does he keep paging me?