Concrete Surface Repair

[steelbeam]

I am removing some concrete walls from a tank in a waste water plant for modifications. When the walls are demolished down to the base slab I am going to require that the vetical dowel bars ( #4 or #5) be cut just above the base slab and then ground flush with the surface. My question is: can the bars be torched off at the surface in lieu of grinding? If someone has done this please let me know, of if there is a better way. Thank you in advance.

 

[ATSE]

When using a torch on the face of concrete to cut off reinforcing steel, if the iron worker is not careful with the angle, there can be a lot of loud popping, and you may get some very localized concrete damage. Not a big deal.
You will need to use a grinder, no matter what cutting method.
Unless you are fully enclosed, cutting a rebar flush is usually not a good idea for exterior exposure. Bars are typically ground back 1" past the surface, then a repair mortar like SikaTop 123 is used to patch the recess.