Pouring concrete

Slig

Whats the procedure for pouring concrete in sub zero temperatures. Usually I would say dont but programmes and timescales dictate.

Is there an additive available for pouring concrete in v-low temperatures. I know it shouldnt be poured below 5degrees and even at that it needs to be covered but what are the options?

Carlow52

talk to the tech people in the concrete plant: they may be able to make it with 'warm' water so as to have it delivered warm. and u then cover it well

Quazzie

Invest in some straw and scatter genorously about an house after pouning. The concrete natually heats as it sets and the straw has the combined effect of containing that heat, keeping the frost off, and keeping air temperatures away. Deciding on what finish is required on the concrete is critical because if its a finished floor I'd highly advise against pouring it. Strip foundation that doesn't require such a flush, smooth finish might be ok.

EDIT: this is an old way of doing this, and there might be a modern equivalent but I've seen this work and used it numerous times.

kkelliher

you can cover it in frost blankets. you can get them in most providers or concrete accessories outlet

Poor Uncle Tom

As the concrete is being constantly mixed until it is poured it will not freeze. The chemical reaction of the setting concrete produces heat itself so this is ok. It is day 2 that is the potential problem, fresh cooling concrete with lots of water around. This is the time for a good covering, as Quazzie said above, straw is the best.

Tip: use slightly stronger N concrete in the colder weather (more heat setting)

Slig

Its a basement slab so its fairly tough stuff already. Thanks for all the advice lads.

Slig

How long after the pour should it be covered, if its being poured at 9 this morning will it be set enough by evening?

Poor Uncle Tom

With today's weather, yes it will be ready, provided it doesn't get too much rain today. If it's hard to the touch this evening it will be fine.

Farmlife

can i ask you how long did it take to set in the end? i got mine poured yesterday morning and today its still a bit soft