Which of the following is NOT a feature listed as required for expansion joints in design phases?

• A. Movement capacity
• B. Water-tightness
• C. Color
• D. Low noise emission

Answer: (C)

Expansion joints are specified in design phases to guarantee the joint can accommodate expected movements, keep water from penetrating the structure, and minimize noise and vibration in the surrounding environment. Movement capacity ensures the joint can slide and flex as the bridge deck expands, contracts, or shifts. Water-tightness is crucial to prevent water ingress that can cause corrosion, freeze-thaw damage, or deck deterioration. Low noise emission helps meet urban and environmental requirements by reducing the impact of joint operation on nearby users. Color, however, does not affect the performance, durability, or safety of the joint and is not a functional design criterion in typical design phases; it may be considered for visibility or aesthetics, but it is not a required specification.