Expansion joints should be installed when?

• A. as late as possible
• B. as soon as possible
• C. during construction
• D. after completion

Answer: (A)

Expansion joints are there to absorb the long-term movement of the bridge deck from temperature changes, shrinkage, and load. Installing them as late as possible means you wait until the concrete has cured and the deck has settled enough that you can size and seal the joints to match the actual movement the structure will experience in service. If joints go in too early, they can constrain movement, induce cracking around the joint, and interfere with subsequent pours and finishing. Waiting until the deck has reached adequate strength and stability also ensures the joint gaps, sealing, and anchorage will be correct and durable when the bridge is opened to service.