Renovating Existing Concrete Beam

[bldgdesign]

Can anyone lead me to literature that would apply to cutting an existing 10" wide by 96" deep concrete beam in half (depth) and adding external reinforcing to strengthen the beam. The initial thought is to bolt channels to each side of the beam and then cut the bottom of the beam off. The channels would act as tension reinforcing. All stirrups would be cut; how to reinforce for shear? Will Channels act as shear reinforcing also?

Or just design the channels to support the entire load and use the concrete beam as a giant spacer. Load will be transferred from concrete beam through channel fasteners to channels. Any thoughts? Thanks.

 

[JAE]

Or just design the channels to support the entire load

Yes - if you cut half the beam off depth-wise this is what you'll have to do. Keep in mind that there would also be load-transfer to the channels so there would be an instantaneous deflection of dead load downward. Might need some pretty stiff channels to keep these deflections under control.

 

[hokie66]

A 96" deep concrete beam is a seriously major structural element. In reducing its depth by half, I agree that the new structure should support the entire load, but doubt that available rolled steel channel sections will do the job. Does this beam have a lateral loading function as well as gravity?

 

[paddingtongreen]

Can the channels transfer the reactions to the supports at the ends? The ends of the beam will be compromised beyond use for shear transfer.

Michael.
Timing has a lot to do with the outcome of a rain dance.