Bridges & Highway Structures
Highways England Design Manual for Roads and Bridges document CD 357 Bridge expansion joints, specifically sets out the requirements for the design and specification of expansion joints for use in highway bridge decks. It also provides supporting advice on the selection, installation, management and maintenance of various types of expansion joints.
This important UK Highways Engineers Guide states:
“Bridge deck expansion joints can be installed at the transverse joints between the end of the bridge deck and abutment ballast wall, or between adjacent decks in non-continuous multi-span structures.
Expansion joints can accommodate thermal and other movements that occur at the ends of the deck, while providing a level, skid-resistant running surface, capable of supporting the required traffic loads, and managing the drainage of surface or sub-surface water to avoid leakage through the joint.
A variety of proprietary joint types are available to suit different structure types and movement ranges.
Expansion joints, and their constituent components, generally have a working life significantly shorter than the design working life of the structure itself, hence thought needs to be given at the design stage of how the joints are to be maintained or replaced, while minimising delay or disruption to road users.
The generic expansion joint types covered by this document are described in Appendix A. of CD357.
The Guideline for European Technical Approval applicable to bridge deck expansion joints, ETAG 032 [Ref 9.N] is discussed in Appendix B, along with the Declaration of Performance for each of the generic expansion joint types referred to in Appendix A.” (as well as their equivalent in BD 33).
The generic types of bridge deck expansion joints that are listed in the guide include:
Part 2 – Buried expansion joint Type 1 – Buried joint under continuous surfacing Part 3 – Flexible plug joint Type 2 – Asphaltic plug joint Part 4 – Nosing expansion joint Type 3 – Nosing joint with poured sealant and Type 4 – Nosing with preformed compression seal Part 5 – Mat expansion joint Type 5 – Reinforced Elastomeric Part 6 – Cantilever expansion joint Type 7 – Cantilever comb or tooth joint Part 7 – Supported expansion joint Not covered Part 8 – Modular expansion joint Type 6 – Elastomeric in metal runners
We should be clear to say here that the provision of these complete mechanical bridge deck expansion joint systems is outside of the scope of Emseal joint sealing systems. However, where appropriate for many of these systems, their service life can often be increased, potential structural damage avoided, as well as lengthy road closures and costly replacement being prevented, by using the Emseal BEJS system to make ‘shorter’ term / intermediate or perhaps ‘temporary’ holding repairs by replacement of just the central movement section of these joints.
All Bridge Structures Can Benefit from Emseal Joint Systems
This ‘temporary’ period may in fact be for several years as evidenced by our experience in the USA and Canada, where this concept began as an innovation from several state DOT’s (Departments of Transport). This approach has now also been picked up by several Highways Engineers and their term contractors in the UK, as it provides a fast and very cost-effective solution to replace deteriorated central sealing areas of such joint systems. This ensures that watertightness is maintained and the rest of the structure is protected, whilst future major repairs and overall replacement can be fully developed, planned and costed, including all of the deeply unpopular closures and delays required for this sort of major structural works, right across our roads network.
In addition to bridge deck expansion joints, the Emseal BEJS solution has also proven to be the ideal approach for sealing several other types of movement joints on bridge structures, especially when extruded sealants and other traditional sealing systems are not suitable or have failed. Importantly in these situations the responsible bridge / structural engineers must make their own individual decisions e.g. through evaluation and assessment of the alternative option, then to select the most appropriate engineered solutions for their specific joint sealing requirements.
Emseal CAD Drawing : Bridge Joint Repairs: Asphaltic Plug
Emseal CAD Drawing: BEJS Nosing - Section Replacement
Interestingly our work in this area was once all for refurbishment projects, but now there is significant adoption for new works as well. In the UK we have recently been involved in providing the Emseal BEJS system to solve difficult joint sealing situations for Parapet wall joints, where high movement capabilities were necessary but with a variable joint width. Another recent requirement was for sealing Wing wall joints that were subject to a joint movement capability that was potentially 100% of the joint width, plus these also had to be backfilled and remain securely watertight to support the extended service life required of these important structures.
For any specific bridge movement joint requirements please contact NCC to provide support and advice to help you to solve bridge deck expansion joint leaking and maintenance problems, as well as to find solutions for any other expansion joint sealing requirements Take advantage of the proven Emseal systems performance on your bridges and highway structures, please call 01257 266696 or you can email: firstname.lastname@example.org
In North America the Emseal BEJS systems have had such success in recent years that the company has now also formed the Emseal Bridge Division with a dedicated support team working with NCC for the UK. The Emseal Bridges Division also has a dedicated USA website that contains a lot of useful bridge related information that you can view here: https://www.emseal.com/bridge-expansion-joint-division/