I am interested in removing a garage concrete slip (31"Wx8'4"Lx1.5"H) to accommodate a storm shelter (4'x8'). The slab is post tension. The project entails a diamond blade set to cut at a height of 1.25", chipping away at the concrete, grinding to garage floor level. Do you think this is a good solution? Can the vibrations affect the post tension cable slab foundation. The shelter weighs about 2,000 lbs and we have been informed that building up the concrete is not a good option because of bonding the new with the old.
I would challenge not being able to bond a portion of a new pad to old concrete. I have used latex based bonding liquid to skimcoat to old concrete. If the floor has been sealed or painted, such that it won't absorb water, might require a surface grinding.
As fully supported pad over a pad, no bonding is even necessary.
Its not clear from your information WHY a interface/overlap area is necessary (presumably IN the garage).
If removing the 'lip' is the easier option, that should be alright, unless some rebar or reinforcing lath is embedded in the lip.