Steel Jacketing for Concrete Column

I have a two-story old existing building. Core tests of some columns show that concrete of some columns are failed , and the concrete strength is 50% less than design strength. We are are in stage of using steel jacketing ( plates & angles) to strengthen these rectangular columns.
I need to know how to calculate this jacketing components as per ACI , which ACI code I can use, and if there are there different ideas for steel jacketing.
In case of columns at expansion joint where 1 or 2 sides of column are not accessible to put plates , what would be the solution?


The most common fix is to place new rebars and concrete around the existing column per ACI. If you’re using steel, the design should be by AISC.

Above is a snippet.