Advantage of using chemically activated resin for repairing is:
ADVANTAGES AND DISADVANTAGES

Better initial fit, which is because the curing is carried out at room temperature. Thus there is less thermal contraction.
Color stability is inferior to that of heat cure resin, due to subsequent oxidation of the tertiary amine.
Slightly inferior properties because the degree of polymerization of self curing acrylics is less than that of heat cured ones.
For repairing dentures, self curing resins are preferable to heat cured resins as heat curing causes warpage.
They can be polymerized at room temperature
They are easy to manipulate
Easy to handle
Cheap in cost