I see rebars with several different shapes of deformations on them. Is there any record showing which deformation patterns develop the best bond?
As far as we know they are all about the same. All bars must meet ASTM standards for sizes, shapes, angular direction and spacings of deformations as set forth in ASTM A 615, "Standard Specification for Deformed and Plain Billet-Steel Bars for Concrete Reinforcement." Each pattern is a sort of trademark identifying the manufacturer. A key to the identity of the patterns may be obtained from the Concrete Reinforcing Steel Institute, 180 North LaSalle Street, Chicago, Illinois 60601.