Our experience is that a one-year waiting period is not needed for concrete that is well made, well finished, of adequate strength, has undergone a short period of air drying, and has an effective air-void system. Concrete that does not meet these criteria is always vulnerable to scaling when it becomes saturated and freezes. De-icing chemicals increase that vulnerability and may lead to scaling in concrete that might otherwise have performed acceptably despite being marginally air-entrained or having surface defects caused by improper finishing.