Vertical Cold Joint in Concrete Beams

[NewbieStruct]

I have 100' feet long continuous concrete beam with columns at every 20'. Do I need to call out the locations of a cold joint in the drawings? I am guessing the contractor will not be able to pour the beam entirely in one pour. If yes, what are the locations that are appropriate. One of our engineers is telling me it should be at the columns. Shouldn't the cold joint be at the location with the minimum moment and shear (about 1/3 of the span of an interior beam)?

 

[hokie66]

100' is not long, so there is no reason not to pour this all at one time. But if you have to make a construction joint, you could centre it over a column, or else put it at centre span, where the shear is minimal.

 

[ron9876]

Agree with Hokie that 100' isn't that long. If a joint is needed I would requie it in middle third of sapn.

 

[NewbieStruct]

Thanks Hookie & Ron. I will show control joints in the middle third of the span. This is a repeat building done by another engineer before and the contractor who is going to do the job asked us to locate control joints for the beam.

 

[hokie66]

Get the nomenclature right. This is not a control joint, just a construction joint. I have never understood the "middle third" bit. Midspan is the best place, unless minimum shear occurs somewhere else.