How do expansion joints help bridges respond to hot and cold temperatures?

In bridge engineering, materials naturally expand and contract due to fluctuations in temperature. If a bridge were constructed as a single, rigid piece, these movements would create internal stresses capable of damaging the structure.

To mitigate this, engineers incorporate expansion joints into the bridge deck. These joints act as intentional gaps that provide the necessary space for the structure to move safely as it changes size.12

Additionally, engineers use bearings at the abutments and the tops of piers to complement these joints. These components allow the bridge to react to varying temperatures without subjecting the materials to detrimental stress. In specific designs, such as arches, engineers may also utilize hinges to further reduce the stresses caused by temperature-induced movement.2

Would you like to learn more about how other structural elements, such as bearings or hinges, contribute to the overall stability of a bridge?