What is the role of expansion joints in managing thermal movement in a bridge?

The role of expansion joints in managing thermal movement in a bridge is to accommodate the expansion and contraction of the bridge deck caused by temperature changes. Bridge decks expand in warm weather and contract in cold weather. Without expansion joints, these movements would induce significant stresses in the bridge structure, potentially leading to cracking, buckling, or other forms of damage. Expansion joints are designed to provide a gap in the deck that allows for these movements to occur freely, preventing the build-up of excessive stresses. They also accommodate movements due to creep, shrinkage, and traffic loads. Proper design and maintenance of expansion joints are essential for ensuring the long-term durability and structural integrity of the bridge.