BRIDGE EXPANSION JOINTS: AN INTEGRAL PART OF BRIDGE CONSTRUCTION

Expansion joints is an assembly designed to hold materials together during fluctuations in size. This can be caused by a number of factors, most commonly, changing temperatures, vibration or structural movement. The movement in these materials is absorbed by the expansion joint, preventing damage to the structure itself.

Common uses in construction include road expansion joints, rail track expansion joints and joints in large concrete slabs. One of the most common uses for expansion joints is on bridges. Bridges bending and moving under environmental strains can have catastrophic consequences. Bridge expansion joints are an essential feature required to maintain the structural integrity of a bridge.

The Different Types of Bridge Expansion Joints

Expansion joints are designed for three different types of movement, being:

Expansion joints for small movement:
- This includes joints like compression seals and pour in place seals.
Expansion joints for medium movement:
- Such as gland seals.
Expansion joints for large movement:
- Alike finger joints and modular joints. Also suitable for large movements are Mageba expansion joints, a high quality water tight joint system invented by the Swiss.

How Does Temperature Affect Bridge Expansion Joints?

Cold weather makes a bridge contract. This results in the bridge getting shorter, where the expansion joint is doing exactly as expected – expanding. Hot weather, however, makes the bridge expand, increasing its overall size and length. This is when the bridge joints contract in on themselves, creating the extra space required for the bridge to move.

What If A Bridge Has No Expansion Joints?

You can think of a bridge like the human body. Our bodies have over 300 individual joints in them, allowing us to move. If we didn’t possess these joints we would be completely rigid. Any small movement causing the possible break or tear of a part of our body. A bridge functions in a similar way. It requires the ability to move and fluctuate. There’s no way to completely avoid the effect of external influences like temperature, humidity and pressure, so we mitigate this problem by installing expansion joints.

Do Expansion Joints Last Forever?

Bridge e xpansion joints are also there to protect bearings and steel components underneath bridges. A bridge without these joints will not endure a long lifespan. Not usually visible as a large part of the structure, expansion joints do a whole lot to help keep a bridge up. It’s important for regular maintenance as bridge expansion joints typically have a lifespan of around 10 years and can become subject to corrosion in particularly wet areas.

Raw Worx Experience With Bridge Expansion Joints

Concrete expansion joint replacement can be a costly and time consuming process. Without qualified professionals at the helm, you risk the safety of anyone that uses the final product. Our extensive experience in bridge maintenance and repair has allowed us to learn a lot about the functions and importance of expansion joints. As one of the most respected bridge expansion joint contractors in Australia, you can trust that we prioritise a durable and safe final product that passes the Raw Worx seal of approval.

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