General Contractor Practice Exam

What factor can significantly affect the adhesion of epoxy coated steel in concrete?

1. Surface preparation

2. Environmental temperature

3. Concrete mix design

4. Reinforcement spacing

The correct answer is: Surface preparation

Surface preparation plays a critical role in ensuring the adhesion of epoxy-coated steel to concrete. Proper surface preparation involves cleaning the steel surface to remove any contaminants such as oils, dust, rust, and existing coatings that could interfere with the bonding process. The roughness or texture of the surface is also important; a properly prepared surface can enhance mechanical bonding between the epoxy coating and the concrete. If the surface of the epoxy-coated steel is not adequately prepared, it can lead to weak points in the bond and potentially result in delamination or failure of the bond over time. Therefore, ensuring the surface is free from impurities and has the right profile for bonding is essential for the long-term performance of the structure. While environmental temperature, concrete mix design, and reinforcement spacing can influence various aspects of concrete applications, they do not directly impact the physical interaction between the epoxy coating and the steel rebar to the same degree that surface preparation does. Thus, recognizing the importance of surface preparation is crucial for achieving strong adhesion and ensuring the longevity of structures that use epoxy-coated steel.