Which two expansion joint types are commonly used on bridges?

• A. Modular joints and neoprene/rubber compression joints
• B. Ball joints and hinge joints
• C. Finger joints
• D. Expansion foam joints

Answer: (A)

Bridge expansion joints are designed to absorb longitudinal movement while keeping the deck watertight and transferring loads smoothly as temperature and traffic cause movement. The two most common types you’ll see on bridges are modular expansion joints and neoprene/rubber compression joints.

Modular expansion joints are made of a series of interlocking blocks or buckets with bridging plates and seals. This arrangement lets the deck slide past each joint module as it expands or contracts, making them capable of handling large movements typical of longer spans. They’re durable, relatively easy to replace in sections, and provide good load transfer across the joint.

Neoprene or rubber compression joints rely on the compressive squeezing of a neoprene/rubber element between abutting surfaces. They’re especially useful for shorter spans or sections with moderate movement and a need for a simple, watertight seal. They’re typically easier and cheaper to install and maintain for such applications.

Other options don’t fit as expansion joints on bridges. Ball and hinge joints are bearing-type connections rather than movement-absorbing joints. Finger joints are more common in joining concrete elements or pavements rather than bridge deck expansion joints. Expansion foam joints aren’t the standard durable solution for bridge deck movement and sealing.