concrete in large planters - curing

Old 05-05-04, 11:42 AM
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concrete in large planters - curing

Let me explain this a little, before I get to the questions. We live on a curve in a road. If someone were to miss the curse they would definately go in our yard, and maybe into the side of the house. I would like to minimize this possibility if I can.
The speed limit is 25mph, but I'm sure there are 40mph+ drivers on this road sometimes.

What I would like to do is: use large half barrel planters, fill then about 3/4 with concrete, then fill with dirt and plants on top. I figure one planter about every 4 feet should work.

My question is regarding the concrete. What kind should I use? Is Quikrete acceptable? I think I can mix this in the barrel, but will the water get soaked into the wood? Should I line the barrel with plastic? What will the cure time be on something like this?

What do y'all think? Will this work? Do you have any other ideas?

Oh, and how much does concrete generally weigh per square foot? What do you think the final weight of one of these barrels will be?
Old 05-05-04, 08:32 PM
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I think you're looking at a potential lawsuit. Roadway crash barrier protection is not in your jurisdiction.

If you feel the need look into placing ballads or crash barriers fully within your property (toward the house - not near the roadway). A chain link crash fence is another way (they ain't pretty, nor meant to be). Otherwise contact the city or county engineer about installing W guardrail. Back your case up with statical data of accidents in the region.
Old 05-06-04, 04:33 AM
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What 2000 said.

You definately want to be sure those barrels are completely on your property. To answer your questions: Quikcrete would work fine, it'll get about 75% of full strength in about 7 days. As far as curing, I wouldn't worry about it too much for what you're using it for; once it receives its initial set (about 12-18 hours), you could cover it with plastic and sprinkle it with water to keep it damp. Don't know why you couldn't mix it in the barrels.

Generally, concrete weighs 150 pounds per cubic foot, dirt is about half that depending on type of dirt and how moist it happens to be.

What 2000 said. If you just filled them with dirt, it would be much easier to defend if you got involved in a lawsuit. Putting concrete in a barrel planter is not a "normal" practice. Having said that, in today's world, anyone can sue anyone for anything, regardless of how reasonable or how outrageous.

Old 05-06-04, 12:08 PM
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3/4 inch of concrete in the bottom of a 1/2 barrel is not going to do much to stop a vehicle. The barrel will just break apart and the car will roll right over the concrete. I would just fill them with dirt and plant your flowers.
Old 05-06-04, 07:41 PM
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The planters will be completely in our property. So if someone were to miss the curve, go through about 15 feet of park property, then go into our yard and hit the planters, I think they would lose the chance of a lawsuit.

Our house has been hit once in the past that we know of. Not much damage, pparently the car just rolled into it.

You can see a simple drawing here:

The green area is a small park entrance. The teal area is the house. The red arrow is the direction a car would most likely take if it missed the curve. And the small blue things are the planters. The drawing is not perfectly to scale.

Now that we have covered that. Bruce mentioned that filling it with dirt would be closer to normal. Very true. But I'm thinking now about possibly just using sand or gravel. And mentally visulizing how many bags of sand/gravel I could fit in half of a 1/2 barrel might work. It's not going to stop a speeding car much, but it should slow a car down some.

Joed, I'm wasn't talking about 3/4 inch of concrete, I was more thinking 12-14 inches, depends on the barrel. Just enough to reach the bottoms of most cars.
Old 05-06-04, 10:44 PM
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Now that things are clear (details help) a more effective way would be build a curved wooden guardrail. Essentially it's a sacrificial fence that would deflect the blow, and slow the vehicle when the rail and brace breaks and the posts sheer.

If you're convinced about filled containers: water absorbs more energy than solids. It's the reason that many crash cans are filled with water. The idea is ineffective without a base that sheers and sealed containers that deform before total collapse.

Slowing the vehicle without causing greater injury to the occupants is the point. Like it or not, when you do these things you're responsible for your actions and the actions of others..

Before doing either, find out what the legal setback from the road is. This could be from the center or the apron. The same for the park.

If a guardrail is of interest: 8x8s on the ends - outside corners trimmed at 45 deg. to round (no sharp edges). Notch the depth of the rail (1-5/8 * 4 inches deep) on one side (no exposed edges). Form a gentle arch with the infill posts(4x4s or 6x6s), Attach the rail (2x8 or 2x10) with carriage bolts. The 2 x stock (brace) with angled ends (below is scribed to the curve and fit to the posts; attached with screws.

If 6x6s are used for infill & you plan - the posts can be nothced slightly for the braces. It will help to distribute the load.

Don't over build. It should fail on extreme impact, without killing someone.

[] [] [] [] []
\ brace /
Old 05-07-04, 08:49 AM
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Thank you for all the info and help.

I have done a quick drawing of what I think you are describing.

I figure on using the same post size for all the posts, instead of 8x8 ends and 6x6(or 4x4) middle posts.

I have drawn in the smoothes corners as you mentioned. If there are any major issues in the drawing please let me know.

The frost line here is 24 inches. Should I set the posts that deep or deeper for more strength?

Your part about the barrier breaking is well taken. I don't want to hurt anyone. Just prevent them from hitting the house. That corner room is the baby's room.

I don't know what "setback" is. I know the county owns the first 10 feet from the curb. And this rail (or whatever I put there) will not go outside our designated property on the sides or towards the street.

I know we are getting a little off topic now since we are talking about the railing. So I will toss in a conrcrete question, Should the posts be set in the ground "on top of" the concrete, or should they be "in" the concrete?
Old 05-07-04, 09:29 PM
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A setback is an A to B distance that you cannot build within. For example, side yard clearance or setback: the distance from A (usually a property line) to B (where physical construction may begin - including projections and overhangs).

The county owns the first 10 feet from the curb. There may or many not be an additional distance from that point or some other point (middle of the road or apron)that you cannot physically attach anything to the ground, other than a mailbox on a break away post. Ask the building department or county engineer. If underground utilities exist ask the governing body. Under the circumstances it would be unwise to guess, because a volition is an automatic excuse for a lawsuit... regardless of how many other things you considered.

Should the unfortunate happen, you want to be able to demonstrate (1) due consideration, (2) reasonable actions (3) you were within the bounds of the law (4) that expense wasn't a primary motive.

Not quite on the design. Below is an ASCII rendition.

Consider a bow. Push against it; it straightens.

Soon the ends of the rail will spilt from weathering and shrinkage. When it straightens you're relying on the bolts, the grain, and thickness of the wood.

The notch (rabbet if you prefer) helps to ensure an outward thrust of the ends before they overturn or snap. With a slight curve the straighten of the rail absorbs energy. The rail end is not exposed. (No splinters or torn clothes while walking by, or edges to catch metal parts on). Obviously the notch should be against the grain, not parallel to it.

Notching intermediate posts isn't necessary.

Bolts alone: they are wedges (most likely parallel to the grain). Think about it.

Slightly trimming the post corners at 45 degrees helps to reduce splitting, and (no sharp corners).

The horizontal brace behind the rail (between each post) adds some strength, and tends to distribute the force over the entire unit; through all of the posts. It supplies a
twisting motion the to posts also.

A suggestion for the post holes: at least 6" below the frost line; 4" of gravel in the bottom. Add 2" of gravel when setting the posts. Compact soil to within 12"; then concrete.

Painting it phosphorescent white, with traffic paint is another suggestion.

Use this as a guide. It's not a prescription.

/XXXX|_\__\__\__\ rail_\_\_\_\__\_\_\__\ \_\_ \__\___
|XXXXXXX|\ ------------------------------------|XXXXXX|
|XXXXXXX| /////////////////////////////////////|XXXXXX|
\______ _| =====================|______|
\\\\\\\\\\\\^^^^^^^^horizonal brace^^^^|||||||||||

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