Concrete column strengthening
Concrete column strengthening
(OP)
We designed the concrete column for our new 14 stroies apartment building,the first two floor are parking garage. couple of the columns were designed 8ksi but the they were built by 5ksi concrete. We tried to use FRP Composites to strengthen the column but those columns are size 24inches by 12 inches because of the limit space of parking lots. From ACI 440-- the high aspect ratio of the column sections (B/H) of 3.0 or higher exceed the limit allowed by ACI 440 for FRP confinement so the FRP may not be effective in confining the columns.
Except the approach for strengthening columns with lower strength is by enlarging them, which is hard for the parking space, could any other solution work in this situation?
Except the approach for strengthening columns with lower strength is by enlarging them, which is hard for the parking space, could any other solution work in this situation?






RE: Concrete column strengthening
RE: Concrete column strengthening
csd
RE: Concrete column strengthening
RE: Concrete column strengthening
I am not sure, how placing steel jacket will enhance the capacity of the column. All the dead load is already on the column. For the steel jacket to be effective, it needs to be secured with the column in the absence of the dead load. He probably can choose to jack the floors above while wraping the steel jacket.
RE: Concrete column strengthening
RE: Concrete column strengthening
RE: Concrete column strengthening
I would recommend testing the in-place columns, and replace them if they are not correct.
RE: Concrete column strengthening
If so 80N/mm2 concrete is not so easy to achieve, the R&D is certainly not worth it for a couple of columns 600 x 300mm.
If this is only 2 columns each 2 storeys high why not strut and then replace with concrete encased steel columns. You would need shear studs into the foor slab.
RE: Concrete column strengthening
8ksi = 55N/mm^2
5ksi = 35N/mm^2
Both are fairly readily available these days.
csd