Quikrete 50 lb. Q-Max Pro Concrete Mix is a fiber reinforced, rapid hardening concrete that can be used on construction jobsites, as well as, for projects around the house. This concrete mix provides superior workability and finishing characteristics and resists cracking. Q-Max Pro Concrete Mix is air entrained for improved freeze-thaw durability and contains a corrosion inhibitor to protect reinforcing steel from erosion. This is an ideal concrete mix for both the professional and the Do-It-Yourselfer because of its unique capabilities. Color: Gray.