Anyone who is skilled in concrete and can give some advice.. I've cast a slab at 110 X 70 X 4 cm... Reinforced it and now traces of the reinforcement are visible on the surface of the slab.. I'm going to cast another slab and would have preferred to avoid reinforcing.. The slab will rest on a frame with four legs in the corners and a longitudinal beam in the middle of the table.. There will be about 30 cm between the beams the slab will rest on...
Does anyone have insight on this?
Does anyone have insight on this?
Diversearbetare
· Göteborg
· 11 246 posts
Would not hesitate to use reinforcement. It's for safety above all. A kid crawling under the table while someone harshly puts down a glass on a fracture point can end very badly (you do the math!).
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What did you reinforce with? Root mesh usually works fine without leaving any marks on the board.
You could also try with fiber-reinforced concrete, but it might be trickier to achieve a nice surface then...
Good luck with the new board!
You could also try with fiber-reinforced concrete, but it might be trickier to achieve a nice surface then...
Good luck with the new board!
So you really believe that a coffee table can crack from a water glass? Sounds very strange to me... Fiber-reinforced concrete is not stronger than regular concrete. I have spoken with manufacturers of fiber-reinforced concrete and it has no advantage when it comes to reinforcement or not. The question is whether it's needed...
Well, you should reinforce. The reason you see the reinforcement now is that you've got a different surface texture where the reinforcement is. Therefore, you should put it in at the very last and then work the concrete as little as you can.
Much of the structural differences disappear when you sand the slab.
By the way, I'm going to cast a bunch of steps for a welded steel staircase tomorrow.
Much of the structural differences disappear when you sand the slab.
By the way, I'm going to cast a bunch of steps for a welded steel staircase tomorrow.
There are many reasons not to reinforce, but on the other hand, you may have to reinforce.MB77 said:
But clearly, it would be easier to get a nice surface all around and on all edges without reinforcement. It would be possible to vibrate for a long time without worrying about the reinforcement sinking down. I'll have to cast a new slab and add the reinforcement as late as possible. The problem is that I want to mix the concrete loosely so that it flows, and of course, this reduces the load-bearing capacity...
I'm even considering placing a slab at the bottom of the table to avoid reinforcing, but we'll see...
I used a 5mm reinforcement mesh on the latest slab, and as mentioned, there were clear marks from the reinforcement...
Cast in two stages, first the part that will become the surface.Tokv41 said:
Let it cure to about 75%.
Then you add the reinforcement and finish casting.
As mentioned, you should add the reinforcement last of all, and after that, you shouldn't vibrate at all. Just "level off" the form.
I have cast kitchen countertops (with undermounted sinks - once and never again!) in fiber-reinforced concrete. I can't say I liked it very much. But it's probably a matter of taste. However, there was no difference in grinding it compared to regular concrete.
I usually mix 50/50 fine concrete and coarse concrete.
I have cast kitchen countertops (with undermounted sinks - once and never again!) in fiber-reinforced concrete. I can't say I liked it very much. But it's probably a matter of taste. However, there was no difference in grinding it compared to regular concrete.
I usually mix 50/50 fine concrete and coarse concrete.
I hung the net last, but then you have to scrape everything off, and then you lose the reinforcement. But I'll try mixing the concrete harder.
What is the advantage of mixing fine and coarse concrete?
Another thing was that some edges became crumbly. Not completely nice, simply put. I guess it's solely because you weren't careful enough to press the concrete in place?
What is the advantage of mixing fine and coarse concrete?
Another thing was that some edges became crumbly. Not completely nice, simply put. I guess it's solely because you weren't careful enough to press the concrete in place?
Sounds like you have too much water if the reinforcement sinks straight through.
You can't dilute concrete with water to make it looser. It's not a solvent but an integral component that chemically binds when the concrete cures. Too much water results in weak concrete, and you risk it cracking.
You can't dilute concrete with water to make it looser. It's not a solvent but an integral component that chemically binds when the concrete cures. Too much water results in weak concrete, and you risk it cracking.