Coated reinforcement compared to uncoated "black" steel has what difference in bond strength with mortar?

Coated reinforcement, such as epoxy-coated rebar, is designed to enhance the durability of the steel by providing a barrier against environmental elements that can lead to corrosion. This coating can also improve the bond strength with mortar or concrete because it tends to create a better interface between the reinforcement and the surrounding material.

The surface of coated reinforcement typically provides a rougher texture than uncoated "black" steel, which can lead to increased mechanical interlock between the steel and the mortar. This enhanced interlock contributes to greater bond strength, as the mortar can adhere more effectively to the surface of the coated steel.

Moreover, since coated reinforcement is often used in environments where corrosion is a significant concern, its ability to maintain bond strength over time even in challenging conditions further emphasizes its advantages over uncoated steel, particularly in terms of longevity and structural integrity. Thus, the bond strength of coated reinforcement with mortar is indeed greater than that of uncoated steel.