Higher strength concrete for massive pours

[ramihabchi]

Once I have been told that for massive amount of pour it is impractical to use high strength concrete because mixer trucks will heat up too much.what compressive strength is the upper limit for vast raft foundation 1m thick?

 

[jayrod12]

I wouldn't say that a 1m pour is that special. How large is the raft? What are the consequences of cracking being present in the top of the slab?

 

[BridgeSmith]

What qualifies as "mass concrete" is not determined by volume, but rather the least dimension being more than a certain value. That value varies depending on the ambient temperature. The typical issue with mass concrete pours is the temperature differential between the interior and the surface during curing. A 1m thick slab shouldn't cause an issue unless the air temperature is low and the top of the slab is not insulated.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[JedClampett]

And why do you need such a high strength pour? Is it bending (unlikely) or shear (possibly, but maybe a slightly thicker slab of lower strength concrete would be economical)?