What is a common method to enhance the bond between concrete and rebar?

The method of roughening the surface of the rebar is effective because it increases the surface area that comes into contact with the concrete, which enhances the mechanical bond between the two materials. By creating a textured surface on the rebar, it allows the concrete to better grip the rebar as it cures and hardens, leading to a stronger overall composite material. This improved adhesion reduces the likelihood of slippage between the rebar and the concrete during tension or compression forces, thus contributing to the structural integrity of the reinforced concrete element.

Other methods, such as smoothing the surface of the rebar, do not promote a good bond; instead, they reduce the area of contact and can lead to an inadequate attachment. Applying adhesive substances, while effective in some applications, is not a common practice in standard rebar placement and may introduce other potential concerns, such as chemical reactions with the concrete. Using larger diameter rebar could provide increased strength on its own but does not directly address the issue of bond enhancement with the concrete, nor does it necessarily improve adhesion. Therefore, roughening the surface stands out as the most effective method for enhancing the bond.