Pouring concrete in hot weather

[pvcpro]

Hello, we are booked in for a concrete pour tomorrow after lunch and it's due to be really hot weather so just after some advice really.

The trench is dug out and is a the ground has a fair bit of clay in it, it hasn't rained for ages so there has bound to have been quite a bit if shrinkage, the weather is due to change after the weekend with potential rain for a few days, will this cause enough heave in the clay to affect the new concrete strip foundation?
Should I give the trench a spray with the hosepipe today? I'm going to cover the area after the pour to protect it from direct sun and will be reinforcing it with rebar.

Cheers

 

[Notch7]

the trench depth should be such that the foundation sits on stable ground not subject to ground heave -Id be surprised if you have a problem.

 

[^woody^]

There is nothing you can do. Any ground movement is influenced by the ground metres away, not just the trench walls and bottom.

 

[noseall]

Hello, we are booked in for a concrete pour tomorrow after lunch and it's due to be really hot weather so just after some advice really.

The trench is dug out and is a the ground has a fair bit of clay in it, it hasn't rained for ages so there has bound to have been quite a bit if shrinkage, the weather is due to change after the weekend with potential rain for a few days, will this cause enough heave in the clay to affect the new concrete strip foundation?
Should I give the trench a spray with the hosepipe today? I'm going to cover the area after the pour to protect it from direct sun and will be reinforcing it with rebar.

Cheers

We poured ours in clay in blistering heat on Monday. No dramas. If it was a floor slab then I'd have taken precautions. We just let it dry in the sun - no cracking and minimal shrinkage.

 

[JohnD]

in parts of France that are hot and sunny, prep is done in the morning, and slabs (esp. road slabs) laid in the afternoon, so the sun will be past its height, as the new concrete sets and begins to cure. This reduces cracking due to shrinkage and weakness from over-fast drying of the top. Covering then retains moisture.

An added advantage is that the workmen can take the time for a proper lunch as the sun passes overhead.