Capacity of Existing Steel Columns Encased in Concrete
Capacity of Existing Steel Columns Encased in Concrete
(OP)
Hello! I have an existing three steel framed structure which we are adding one story to. The beams and columns are encased in concrete. The building was constructed in 1964. From analysis some of the steel columns are overstressed when the vertical addition loads are applied. Can the concrete encasement be considered to be acting compositely with the columns? The encasement is very rebust. For example, 8WF40 encased in 22x22 concrete.






RE: Capacity of Existing Steel Columns Encased in Concrete
RE: Capacity of Existing Steel Columns Encased in Concrete
Alternatively, you might look at a carbon wrap on the columns - added complexity but it might work.
RE: Capacity of Existing Steel Columns Encased in Concrete
Regarding to the question, steel at your actual service level will be likely in elastic state -it would be quite anomalous to be otherwise- and your aditament should (or at least could) protect the quasielastic behaviour of the existent steel column for any foreseeable new service level loading ... so in general terms there will be composite action, the specifics as pertaining to the design to be cleared in the process.
RE: Capacity of Existing Steel Columns Encased in Concrete