What aspect of concrete surfaces may worsen without the use of a primer?

The correct answer highlights the importance of bonding efficiency in the context of concrete surfaces. Primers are designed to improve the adhesion between the concrete surface and the roofing material applied over it. Without a primer, the surface may be too smooth or porous, resulting in poor mechanical bonding. This can lead to delamination or separation of the roofing system from the substrate over time, especially due to factors like temperature fluctuations, moisture, and structural movement.

Enhanced bonding efficiency ensures that the roofing materials will adhere securely, reducing the risk of peeling or lifting, which can compromise the overall durability and effectiveness of the roofing system. Therefore, if a primer is not utilized, the bonding efficiency between the concrete surface and the applied materials could deteriorate, leading to performance issues in the roofing system.