Fill tall pole with concrete - cure?

[Matt Whiting]

Except that the real issue at hand was stiffness, not strength. That confusion was injected by someone (Nehmo I believe) later in the discussion.

Matt

[Matt Barrow]

Cartoons fool you.

[JTMcC]

I spend well over 100 days a year in Las Vegas many years. We generate a considerable amount of income in Clark County.

You appear to be well out of your area of expertise and you most definitly have little or no practical experience in the area. It's a common flaw in cyberengineers to portray themselfs as experts on each and every topic that comes up. I'm guessing you are there in a big way.

I'd be curious to see just how many posts you have here in cybertude. How, and when, do you actually work??? Or do you work?? Doing what? Engineering "housing"? LOL.

JTMcC.

[Matt Whiting]

Having one's bluff called is so embarrassing. When you can't provide the data you have to resort to insults. How sad...

[JTMcC]

Is there a lot of money in telling a guy (on the net) how to nail his shingles to the roof of his house? lol, now THAT'S engineering, cutting edge I might add, you should author a paper: ) Thank goodness you're here! Those home owner do it yourselfers might cause the collapse of the worlds infrastructure.

JTMcC ; )

[JTMcC]

You probably have the capability, and the time, to do a search on the topic if you don't have the appropriate reference material on hand. I'm running a business and I'm certainly not going to do the search for you, or dig thru the tons (literally) of material here to find information on composite concrete filled tubes/pipes in both big bore and small/slender applications. I have little mouths to feed. Now, if that's what you call embarassing and sad, then you my little man have an embarassing and sad internet existence. To me a sick child is sad, a young Mother dying, ect. And as for embarassing, well I'm pretty imune to that so I can't help you there, but to use those words in the context of a discussion on usenet means you are just a little bit to heavily invested in your cyber identity. Others have probably told you this already. My advise is to turn the computer off every once in a while., get outside in the fresh air, and actually do something. Drive around. You'll feel better. Your world won't revolve around a computer screen. Don't worry, that guys shingles will still get nailed down, roofs have been replaced for thousands of years without you. Maybe you could put a dish up in your backyard for a little outside project? You could use some sch. 160 pipe! Or 3" cold rolled round stock.

JTMcC.

[Bob Morrison]

To all:

I know I promised not to write anymore on this subject, but the following message was e-mailed to me and I wanted to share my reply to show that there are indeed practical implications to my earlier posts on this subject.

First, filling an 8-inch sched 40 with concrete may gain you about 30% more stiffness and it will add mass.

An 8-inch sched 80 pipe will give you a 45% increase in stiffness but may not add the mass you desire.

Filling the pipe can be a tedious job depending on the height of the pole. It takes about 0.35 cubic feet of concrete to fill one foot of 8-inch pipe. A typical bag of Quikcrete makes about 0.60 cubic feet of concrete and so will fill slightly less than 2 feet of pipe.

If we say your pipe is 20 feet long it would take about 12 to 13 bags of Quikcrete to fill the pipe. The cost of the Quikcrete material isn't very much, less than $100. Getting that into a 20-foot piece of pipe is not so easy and cheap. You could hire a pump at $300 per day (not very practical). You could hand mix and haul the concrete up a tall ladder and pour it down the pipe. Possible, but a lot of work. Not to mention that the concrete is now dropping 20 feet and will segregate (not a good thing).

Or you could do what I have been recommending in alt.building.construction, which is pay for a larger diameter or thicker wall pipe and leave it empty. A lot less work to accomplish the same thing.

Now, if you had a large number of these pipes in a solar array of some sort, then it might make some economic sense to buy the thinner wall pipe and use equipment to fill them with concrete. But, I just don't see this as being practical for a "one of" scenario.

[RicodJour]

I'm surprised no one mentioned guy wires - pretty much industry standard for aerial towers, right? If you're trying to eliminate swaying, that's the surest way to achieve that end. Anything else is adding weight and strength where you don't need it and the pipe will still sway.

R

[Kevin Hobart]

replying to Matt Whiting, Kevin Hobart wrote: Air can be depressed. cement can't. I'm sure we can agree air in metal makes metal weaker. A pipe filled with cement would be almost impossible to bend. Vs. the same pipe with only air inside it. So, in answer to the question, I would say that I would go one step further and fill a few sticks of conduit with cement and add them to the pipe, then fill the pipe with cement. Just depends how stiff you want to make it. The "Anchor Cement" sets up in about 10 minutes. I want to believe it cures at just over 7,000 psi in just a day or so. If you wanted to add a little conduit to it , I bet you could double the strength as well. I hope this helped.

[Scott Hall]

replying to Bob Morrison, Scott Hall wrote: You are an idiot, if you fill the pole with sand or gravel it will be immensely stronger than if left hollow. The idea that the concrete cracks has any impact on the strength of the overall strength is preposterous.

[Robert vertin]

replying to Bob Morrison, Robert vertin wrote: What the hell? You are an engineer?? Even if concrete cracks, any deformation is limited to the volume such crack will allow deformation into ... you could fill the pipe with sand and cap it off and enjoy some benefits of this same principle. Have you ever wondered why they fill safety poles with cement ? Duh

[BigRed52]

I had a basketball pole that needed more stability. I did concrete the bottom post from the bottom to about 3ft above ground. Before I filled in the post hole I also put concrete around it. I wanted it to be more stable. When I had poured enough concrete to fill to the top of the first pole, I placed three small steel rods 3ft long down the pipe to add stability. Before the concrete set, I used a rubber hammer to tap around the pole and eliminate as much air as I could in the concrete. I then drove large bolts above and below the joints at various heights. I then put the top two sections on and waited two days to make sure it set well. It did. No vibration at all. It went up in 1995 and I removed the entire post in 2000 with a farm Jack and a chain.

[GirlOnAmission222]

Laughing my ass off here!! This thread.. hilarious. 😂 I would say hi y’all but this thread is 14 years old and some of you may already be ...🤐. I’m a lady looking for information on filling my metal post with concrete before building my dog run. Guess what? I did and.....(insert drum roll) they’re as strong and stiff as fucq! ( Dog run’s built, the dog if’s are happy. Fill the piles, the holes, the pipes with concrete folks, quit overthinking shit. Lol..🤜🏾🤛🏻