At 08:23 AM 7/31/2006, ADRIAN REES wrote:
>Over here in the UK, I am about to "plant" 4 towers, and pour C35 Grade
>Concrete in the bases. Anyone know what is the setting time for this
>stuff, and can it poured in one or two lots ? Getting this amount of
>concrete onto the site is not easy. I live up a mountain, with access
>limited to 4 Wheel Drive vehicles, and certainly a Truck will be near
>impossible to get on site, let alone a Ready Mix Concrete one ! So I may
>have to mix on site, and pour in batches.
You'll want to talk to your concrete supplier.
The "set time" for the concrete can be adjusted to a certain extent (they
do this anyway to compensate for temperature changes.. it's a chemical
reaction, and if you used summer mix concrete in winter, it'll take forever
to cure..) Mind you, this is for "largish" jobs. The local U-kart place
probably doesn't do this.
My experience (which is limited) has been that if you have a 2 or 3 hour
gap between batches, there's a definite non-joining, because the first pour
has already started to set.. it's certainly not a monolithic block.
Obviously, a big monolithic block is better, but the real question is how
do you get multiple pours to join in a mechanically sound way. There might
be some clever way to, for instance, have interlocking grooves, or rebar
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