Can I hang a heavy weight from a concrete ceiling if I reinforce it with fiberglass?
The correct answer here is to not hang the load from points on the ceiling, which will damage the structure and could make you liable for losses due to the damage, but to build a structure that will spread the load on the floor. (I think this was covered in a few previous questions... I'm certain I've given this answer before) You would want to build a structure out of steel, either angle iron or square tube, with legs that will spread your weight load across the floor. Many structures are available pre-made, even ones that fold up flat, for crossfit enthusiasts, or you can always manufacture your own with metal, an angle grinder, and a drill and bolts.