Engineering
Why Bridge Expansion Joints Crack and How to Prevent It
Quick fact
A typical expansion joint can move more than 5 centimeters during a 30°C temperature change, and a single heavy truck can compress it by a few millimeters. Over millions of cycles, this constant flexing and pounding causes micro-cracks that grow into full joint failures, often within a decade if not properly designed.
Why this is interesting
Imagine the deck of a bridge constantly moving back and forth as temperatures swing from freezing winter nights to scorching summer afternoons. Why do those thin strips of metal and rubber—the expansion joints—often crack and fail?