FOI release

Half-joint bridges

Case reference EIR2024/01694

Received 3 December 2024

Published 6 February 2025

Request

Please can you provide a full response to the following questions.

  • How many half-joint bridges do you have?

  • How many of your half-joint bridges have been assessed?

  • Of those assessed, how many have been assessed to CS 466 - ‘Risk management and structural assessment of concrete half-joint deck structures’?

  • Of those not assessed to CS 466, how many have been assessed to BA 39/93 - ‘Assessment of Reinforced Concrete Half-joints’?

  • How many of your half-joint bridges have an assessment rating of less than 44T?

  • Of those that have an assessment rating of less than 44T, how many have been classified as substandard in accordance with CS 470 - ‘Management of sub-standard highway structures’ OR BD 79/13 - ‘The Management of Sub-standard Highway Structures’? With respect to ONLY those structures that have been classified as substandard in accordance with CS 470 or BD 79/13,

  • How many are currently closed?

  • How many are subject to weight restrictions?

  • How many are monitored?

  • How many are subject to other mitigation measures (e.g., propping etc.)? Please describe.

  • How many have subsequently been strengthened?

  • How many have no mitigation measures, yet are substandard?

  • Have you identified any half-joint bridges with specific defects that have resulted in an enhanced monitoring regime? YES/NO

  • If yes, how many? Please describe monitoring techniques and frequency.

In addition to above questions, please feel free to add any further comments that you may wish to have.

Response

We manage the strategic road network (SRN) in England, which comprises motorways and major A roads. Only 'concrete half joints structures' that we manage are included in the responses below.

How many half-joint bridges do you have?

We are responsible for 378 concrete half joint structures.

How many of your half-joint bridges have been assessed?

225.

This includes some structures that have been subject to a numerical assessment not specific to the half joints assessment programme.

Of those assessed, how many have been assessed to CS 466 - 'Risk management and structural assessment of concrete half-joint deck structures'?

27.

Of those not assessed to CS 466, how many have been assessed to BA

39/93 - 'Assessment of Reinforced Concrete Half-joints'? 180.

How many of your half-joint bridges have an assessment rating of less than 44T?

9.

Of those that have an assessment rating of less than 44T, how many have been classified as substandard in accordance with CS 470 - 'Management of sub-standard highway structures' OR BD 79/13 - 'The Management of Sub-standard Highway Structures'?

8.

With respect to ONLY those structures that have been classified as substandard in accordance with CS 470 or BD 79/13,

How many are currently closed?

3.

How many are subject to weight restrictions?

4.

How many are monitored?

6.

How many are subject to other mitigation measures (e.g., propping etc.)?

None.

Please describe.

How many have subsequently been strengthened?

None.

This excludes concrete half joints structures that have had other interventions such as, but not limited to, removal of half joints by introducing continuous decks, permanent propping or other refurbishment works.

How many have no mitigation measures, yet are substandard?

None.

Have you identified any half-joint bridges with specific defects that have resulted in an enhanced monitoring regime? YES/NO

Yes.

If yes, how many? Please describe monitoring techniques and frequency.

30 half joint structures have an enhanced monitoring regime.

Monitoring techniques include the following options, or a combination of options:

· Regular tactile inspections and hammer tapping surveys

· Special inspections using Non-Destructive Testing (NDT) techniques such as crack monitoring with DEMEC gauges, endoscope inspections, tomography, impact echo and acoustic emission monitoring.

These investigations are repeated as required, based on inspection findings.

Documents

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