Concreting Wall & Slab In One Pour

Isn't wet concrete a fluid, though? Won't it slump?

you mean how to work the hydraulics?

Good question.

Yes how!

unless its poored in enclosed form it probably wont work!

It is possible. But the temporary shoring and formwork must be able to not only support the fluid weight of the concrete but also vibrations and construction loads until the concrete has attained sufficient compressive strength.

BUT, if there is a concrete slab or slabs + walls and columns below the one in question, then you had REALLY better know what the heck you are doing, or else you could collapse the entire house of cards killing and/or maiming construction workers below.

You do know how to PROPERLY design the shoring and forms don't you? If not, don't even attempt it........

Look at the sequence. Form the slab and the back and sides of the wall, place the slab, vibrate the slab, add top forming to hold the liquid pressure that will build, add the front of forming for the wall and place concrete. That doesn't seem to be one operation, especially if you want any kind of float or brush finish on the slab.

yes as stated, it can be done.......

but what happens after its done, any expansion joints required or other stresses as it cures.

What is it retaining? or supporting? House?, effluent storage?

No it is not easy. But in some special situations it is done but generally not for large scale jobs.

If one wall shifts or fails the whole project becomes one very large mess that that is doing its best to turn into a solid immovable object right where it is not wanted.

I think septic tanks can be built that way.

It's easier to dig a 'king great hole, and crane in a GRP one off the back of a lorry, though...

Its called a monolithic pour and they can be done. Such pours were required ever time I use to do secondary containment for our large permanent fuel tanks. Your going to need a pretty high slump in the wall section of the pour.

High slump? Nahhhh. I'd specify a w/c of around 0.40 to 0.44 (depending on max. aggregate size, and per ACI 318), 3" max. slump, but use a mid-range to high range plasticizer instead.

I was referring to a 2-3" slump been out of the QC side for a while. PADOT required us to do them for all of our secondary containments and box culverts but we use to fight them all the time because of the extra man hours and cost compared to doing separately.

Guys,

I watched a UK TV programme last night called Grand Designs - this is a weekly program, I believe, which traces a "Grand Design from start to finsih as far as is practical.

Last night we had a couple with limited funds who needed a home in London.

They took 10 years and eventually found a site, and then an Architect.

The plot was tiny, triangular and the build took up the whole plot. They had to get agreement from all of their 17 neighbors before they could start and the neighbours had to agree to their boundary fences coming down for the project and losing the bottom third of their gardens for the duration. Sorry - for Garden read Yard.

Watch and enjoy and Yes, if you are careful you can pour a lot of concrete, 3D , very quickly.

It takes a lot of nerve and a lot of skill and a lot of prep.

I enjoyed watching it and I am no TV hound!

Sleepy

It takes a lot of nerve and a lot of skill and a lot of prep.

and a lot of forms

I saw them put up a 3-4 story building this way in the property next to where I worked. I don't think it took more than a couple of weeks. They put the frames on the ground, poured concrete, and raised the walls up with cranes. Great lunch hour entertainment. I'm sure the cost was a very small fraction of our building which was made of bricks and mortar.

Rixter, what you witnessed is called "tilt-up" construction. It's a very specialized form of concrete construction, as the the reinforced concrete elements has to be properly designed to not only resist the usual building design loads but also the lifting loads. It's very complicated to design!

That would depend on how high the wall is.????