CASE STUDY : TINSLEY VIADUCT

PROJECT INTRODUCTION

Tinsley viaduct is a two-tier steel box girder viaduct which opened in 1968 as a key structure on the near in Yorkshire. The M1 is one of the UK’s main motorway arteries and a key economic link between the north and south of . The upper deck of the viaduct serves the M1 and the lower deck serves the A631 which is part of the strategic road network around Sheffield. The maintenance of Tinsley Viaduct is the responsibility of Highways England and sits in Area 12 where A- one+, a joint venture between Costain, Colas and Jacobs, has the maintenance framework contract.

A key project within the maintenance programme in 2019 was the repair and resurfacing of both lanes of the A631. As one of the UK’s leading road infrastructure repair specialists, Metrail Construction Ltd was selected by A-one+ to carry out the deck waterproofing and associated concrete repairs on the south bound carriageway.

SCOPE OF WORK

The contract awarded to Metrail covered the following scope of work on a total of 18,000sq m of deck and 1850sq m of walkway: • Remove existing waterproofing • Remove existing walkway surfacing • Scrape the main deck to remove any remaining surfacing and waterproofing • Identify and carry out concrete repairs prior to waterproofing • Apply waterproofing, including bond coat, with a proprietary waterproofing system • Apply combined waterproofing/high friction surfacing on the walkway.

HEAD OFFICE : UNIT 13 STATION ROAD INDUSTRIAL ESTATE, HAILSHAM, EAST SUSSEX, BN27 2EY T: 01825 761360 REGIONAL OFFICE : BIG PICTURE HOUSE, PONTEFRACT ROAD, SNAITH, DN14 0DE T: 01405 808230 1 SCOTLAND OFFICE : MAXIM BUSINESS PARK, MAXIM 1 - 1ST FLOOR, 2 PARKLANDS WAY, MOTHERWELL, ML1 4WR T: 01417 397510 CASE STUDY : TINSLEY VIADUCT

PROGRAMME

The works required a traffic management scheme to be put in place to enable two-way traffic on the north bound carriageway which then allowed a full closure of the south bound carriageway. This enabled extended day time working for the resurfacing to be completed.

The Metrail contract for waterproofing and concrete repairs was carried out in two five week phases commencing in May 2019.

ECI with A-one plus meant that Metrail was able offer a reduced contract timescale compared to the programme for the north bound carriageway.

WATERPROOFING SYSTEM

As a specialist in the sector Metrail Construction has extensive experience in the application of bridge deck waterproofing systems and is one of a limited number of companies in the UK licensed to apply the GPC Advanced Technologies (GPC) waterproofing system known as Eliminator.

Formerly known as Stirling Lloyd, GPC is a world leader in the supply of high-performance products in the construction sector.

Eliminator is rapid cure, cold liquid spray applied system based on methacrylate monomers which forms a tough, flexible seamless membrane with no vulnerable joints and is resistant to chemical attack by oil, fuels, brine and dilute mineral acids. Where asphalt is to be laid a bond or tack coat is also applied.

METHODOLOGY

The Metrail scope commenced once the asphalt surface on the main carriageway had been removed down to approximately 10-20mm.

Metrail employed a large caterpillar tracked scraper with a bladed head to remove as much of the remaining surface as possible. The surface then had to be fine milled to remove any remaining traces of the old surface.

HEAD OFFICE : UNIT 13 STATION ROAD INDUSTRIAL ESTATE, HAILSHAM, EAST SUSSEX, BN27 2EY T: 01825 761360 REGIONAL OFFICE : BIG PICTURE HOUSE, PONTEFRACT ROAD, SNAITH, DN14 0DE T: 01405 808230 2 SCOTLAND OFFICE : MAXIM BUSINESS PARK, MAXIM 1 - 1ST FLOOR, 2 PARKLANDS WAY, MOTHERWELL, ML1 4WR T: 01417 397510 CASE STUDY : TINSLEY VIADUCT

Given the age of the viaduct and its concrete deck an extensive number of concrete repairs had to be carried out. These were done using Metaset Rapid Repair Mortar which cures to full strength in 1-2 hours.

The next step in the process was to sand blast the surface and carry out adhesion testing to assure a strong bond for the waterproofing system.

The prepared surface was then primed and manually sprayed with the Eliminator system.

Metrail maintains a highly trained team of experienced spray technicians who were able to carry out the waterproofing against a tight timescale With regards to the walkway, Metrail was able to offer an alternative solution to that used on the north carriageway which was discussed and agreed during the ECI phase.

Rather than use a method of screeding the steel walkway, which had proved time consuming and costly, Metrail proposed the use of Safetrack, which is a GCP product specifically designed to provide a durable anti-skid surface.

Metrail stripped and cleaned the old walkway surface down to the bare steel which was then primed with and waterproofed with Eliminator so that Safetrack could be applied.

HEAD OFFICE : UNIT 13 STATION ROAD INDUSTRIAL ESTATE, HAILSHAM, EAST SUSSEX, BN27 2EY T: 01825 761360 REGIONAL OFFICE : BIG PICTURE HOUSE, PONTEFRACT ROAD, SNAITH, DN14 0DE T: 01405 808230 3 SCOTLAND OFFICE : MAXIM BUSINESS PARK, MAXIM 1 - 1ST FLOOR, 2 PARKLANDS WAY, MOTHERWELL, ML1 4WR T: 01417 397510 CASE STUDY : TINSLEY VIADUCT

CONCLUSION

Tinsley Viaduct was a project that offered us the opportunity to showcase our extensive experience and skills in waterproofing and concrete repair.

The success of the project was based on sound project management, technical competence and close coordination with all the stakeholders involved.

Metrail achieved all the timescale milestones to ensure that the southbound carriage opened on time.

A-one + expressed particular satisfaction with Metrail on this important scheme.

HEAD OFFICE REGIONAL OFFICE SCOTLAND OFFICE

UNIT 13, STATION ROAD, BIG PICTURE HOUSE, MAXIM BUSINESS PARK, INDUSTRIAL ESTATE, PONTEFRACT ROAD, MAXIM 1 - 1ST FLOOR, HAILSHAM, SNAITH, 2 PARKLANDS WAY, EAST SUSSEX, DN14 0DE MOTHERWELL, BN27 2EY ML1 4WR

T: 01825 761360 T: 01405 808230 T: 01417 397510 4