Which of the following is NOT a common problem associated with walks and driveways?

Control joints are not considered a problem associated with walks and driveways; in fact, they are a deliberate feature incorporated into concrete surfaces. Control joints are intentionally placed in concrete to help manage cracking caused by the natural expansion and contraction of the material as temperatures change. Their purpose is to create weak points where cracks can occur in a controlled manner, thus preventing random cracking across the surface.

In contrast, cracked surfaces, uneven surfaces, and improper slope are common issues that can arise with walks and driveways. Cracked surfaces are a result of stress, weather conditions, or improper curing, while uneven surfaces can lead to trip hazards and water pooling. Improper slope can affect drainage, leading to standing water, which can deteriorate concrete over time. Therefore, while control joints are a necessary component for the longevity of concrete surfaces, they are not a problem but rather a preventative measure against potential cracking.