Increase cross sectional area of reinforced column 1

[nasugarus]

Existing reinf column diameter is 400x400mm,height is 3.00m..We have to increase the cross sectional area
to 800x600mm with a total height of 10 mts.This is a warehouse bldg with a dimension of 30x30mts.Is it possible to attach the new column say 600x400mm,note that 3.00m has already been casted afterwhich 3 to 10 mts to be casted as 1.my concern is the bonding between the old and new column from 0 to 3m height..Is is possible and safe,what is the best solution?thank you..by d way 1 side only with at least 10 columns done at 3mts height and 4mts distance center to center casted..

 

[hokie66]

I would guess, but don't actually know from your description, that you will also have inadequately sized footings. If so, the best option at this stage is to hook onto the column reinforcement with a mobile crane and take them out and start over. Even if the footings are judged to be large enough (lateral loads are resisted by other means), the most practical and economical solution is to knock off the columns and cast them the correct size.