Pour concrete frame on plinths

[bighenk]

Hi! I'm working on a project at home and about 2 months ago I cast 6 concrete pillars. Now I've reached the step where I'm going to cast the concrete frame that will sit on the pillars.

The question is, do I need to prepare the tops of the pillars in any way before casting the next stage? Or is it enough to brush off the dust and try to blow it clean?
Best regards, Henke

 

[Dowser4711]

Hello! I'm working on a project at home and about 2 months ago I poured 6 concrete pillars.

Now I've reached the stage where I need to cast the concrete frame that will rest on the pillars.

The question is, do I need to prepare the tops of the pillars in any way before I pour the next stage? Or is it enough to brush off the dust and try to blow it clean?
Regards, Henke

Do you have any rebar attached to the pillars?

 

[bighenk]

Do you have any reinforcing bars attached to the plinths?

Yes, indeed. They are double reinforcing bars that come up and are bent along the frame. And in the frame, there are 2 rows above and below with reinforcing bars all around. Attaching a picture if you ignore the amateur construction 😂

 

[Centano]

I’m a bit curious about what’s going to be built?

 

[bighenk]

Becomes a little curious about what is going to be built?

It is a greenhouse, but it's the kind of greenhouse where you need to build a 50cm wall. So I'm building a solid foundation so there won't be any problems in the future.

 

[jonaserik]

What will be the dimensions of the beam, it looks a bit flimsy and only 3 plinths in length.

 

[bighenk]

What are the dimensions of the beam, it looks a bit flimsy and only 3 pillars in length.

145mm high x 150mm wide. 12mm reinforcement

 

[jonaserik]

According to the photo, it should be a brick base, it is heavy, so reinforce with 2 pieces of 12 mm iron 5 cm from the top edge and equally 5 cm from the bottom edge. It becomes like a square with reinforcement, approximately 7X7 cm. Overlap at joints minimum 40 cm, it's good to use zip ties to hold the iron in place during casting. If you have a good and sturdy mold, you can vibrate with a slightly larger hammer drill with a large bolt on the nose, which is placed against the mold. Do not pour in too much at once but vibrate between additions so it flows out properly and the air is released. Then it will be strong.

 

[bighenk]

According to the photo, there should be a brick base, it is heavy, so arm with 2 pcs 12 mm rods 5 cm from the top and equally 5 cm from the bottom. It becomes like a square with reinforcement, about 7X7 cm. Overlap at joints minimum 40 cm, it is fine to use zip ties to hold the rods in place during casting. If you have a good and steady mold, you can vibrate with a larger impact drill with a big bolt in the nose, placed against the mold. Do not pour too much at once, but vibrate between layers so it flows out properly and the air escapes. Then it will be strong.

So you mean I should have 4 reinforcement rods? I have a real concrete vibrator. But do I need to do anything to the surface of the footings before casting?

 

[neo11]

Looks good, I don't think you need to do anything more.

 

[jonaserik]

Yep 4 pieces, the one with real vibbra, be careful otherwise the form can fail, there will be an enormous pressure on the form with professional equipment, are you on board with reinforcement in square. It is a beam and it should have top and bottom reinforcement to be really strong. Regarding the pillars, if you have iron in them and bent one in each direction, then you're set and don't need to do more with them. Good luck with the construction.

 

[bighenk]

Yep, 4 of them, with real vibration, be careful otherwise the form can cave in, there's an enormous pressure on the form with professional equipment, are you doing reinforcement in a square shape? It's a beam and it should have top and bottom reinforcement to be really strong. With the plinths, if you have iron in them and bent one in each direction then you're good to go and don't need to do more with them. Good luck with the construction.

Yes, I understand what you mean. But I think I'm going to take a chance on what I've already done. 2 reinforcement bars on the top and bottom. I don't have time to redo it to incorporate even more reinforcement. I'll probably lay some of those masonry reinforcements when I get to that step to distribute the strength a bit more. Thanks everyone for the advice/tips.

 

[jonaserik]

You can place a 6 mm järn between the 1st and 2nd shift + between the 3rd and 4th when you are masoning, and that should surely suffice.