Expansion joints are integral parts of our national infrastructure. From bridges to large concrete surfaces such as warehouse flooring, we travel over them every day without giving them a second thought. Infrastructure ages over time and with repeated use must eventually be rehabilitated. Bridge rehabilitation work can range from repairs (patching pavement and painting structural steel) to complete overhauls (steel replacement and bridge deck overlays). Can any of the existing structural components be salvaged and used again during a rehabilitation project? Can expansion joints be reused? Should they be? Below are reasons why expansion joints are candidates for replacement, not reuse.
- Removing the expansion joint material can damage it.
Expansion joints do not simply sit between two deck slabs of the bridge. They are bonded to concrete or steel surfaces with a high-performance adhesive. The high-performance adhesive forms a strong bond between the expansion joint material and the adjoining deck sections. During the removal process, this strong bond must be broken, normally resulting in damage to the seal itself. This damage could compromise the performance of the joint seal material if it were to be reused.
- The age of an expansion joint affects its performance.
Expansion joints are designed to absorb the stress of movement on bridges decks to prevent cracking of the surface. Joint materials do not have an indefinite performance life. As the joints move over time, they are subject to performance degradation. When the time comes for a rehabilitation project, the expansion joint may already be at the end of its useful service life; therefore, when contemplating restoration, a necessary consideration is the length of time an expansion joint has been in service.
- What kind of movement did the bridge experience over time?
Expansion joints are sized based on the width of the deck joint and calculated thermal requirements. If the original expansion and contraction calculations are exceeded by the environmental and live loads on the bridge deck during its initial service life, the performance of the joint can be severely impacted.
- Is there unseen damage?
One of the most common reasons for expansion joint failure is improper installation, which can cause joint material damage that may not manifest itself during its current usage but can be compounded with the additional stress of removal and reinstallation. This can lead to premature failure in the rehabilitated bridge. Additionally, vehicle travel over time leads to damage that is not visible to the naked eye.
Related article: The Importance of Expansion Joints on Concrete Bridge Decks
When bridge structures require rehabilitation, do not plan on reusing expansion joints. Considering the time and money invested in new bridge deck overlays and additional structure repairs, it’s prudent to protect that investment by replacing, not reusing, the expansion joint system.
Check our video in how to Install CEVA 250 Expansion Joint
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