Which joints are used to provide a smooth transition for modern bridge construction or continuous girders?

• A. Steel expansion joints
• B. Bridge expansion joints
• C. Small movement joints
• D. Rubber joints

Answer: (D)

The main idea here is that bridge joints must allow movement while keeping the roadway surface smooth for a continuous girder system. Rubber joints, made from elastomeric materials, provide the needed flexibility to absorb thermal expansion, contraction, and live-load movements without creating a bump or discontinuity on the deck. They can compress, stretch, and shear just enough to keep the riding surface even as the spans move, while also helping seal out water and dampen vibrations. Rigid steel or metal expansion joints tend to introduce abrupt transitions and wear gaps, and small movement joints are intended for limited movement and wouldn’t accommodate the larger shifts that continuous girders experience. So rubber joints best achieve a seamless, durable, and smooth transition between spans.