Which of the following is a line at which the face of the curb meets the top of the payment?

• A. Expansion Joint
• B. Contraction Joint
• C. Control Joint
• D. Isolation Joint

Answer: (C)

A control joint is placed right where the curb face meets the top of the pavement to create a predetermined weak line. This guides cracking to occur along that edge rather than randomly across the pavement, which helps keep the rest of the surface neat and durable. The joint acts to control where stress relief cracking happens due to shrinkage and temperature changes, making repairs and maintenance easier over time. Expansion joints are for allowing thermal growth between sections, isolation joints separate different structural members to move independently, and contraction joints are essentially the same concept as control joints in many codes. So the line at the curb-pavement interface is treated as a control joint.