Concrete Pile Caps

[4wilmar]

As part of the QC team on site I am concerned about heat of hydration and thermal cracking on several up-coming pile cap pours which are over 10 ft thick, 15 ft wide & 20 ft long. However the designers have advised us that they are not really to be considered as mass concrete pours and we need not take any speacial precautions.

1. What kind of cracking might we expect if none of the vertical faces are reinforced and we start off with a concrete temp of about 90 degrees???

2. If some of the piles have been designated as tension piles and the rebar extends only about 3 ft into the bottom of the pile cap, what carries the tensile load up to the column above if there is no vertical steel in the pile cap???

Perhaps I am missing something, but any comments would be greatly appreciated as the contractor and Engineer of Record don't seem very concerned about any of this.

 

[hokie66]

I would be concerned about the same things as you are. 90 degree concrete is too hot. As far as I am concerned, 10 ft thick is mass concrete. As to transfer of the column uplift to the piles, it would depend on the magnitude of forces as to whether there needs to be reinforcing for development.