Articles about Composites UK

Colinton Dell is a steep-sided gorge and wildlife refuge on the Water of Leith, just north of the old village of Colinton on the outskirts of Edinburgh.
Today walkways and a cycle path take visitors to the ruined Redhall Mill and past Kate's Mill, where paper for the Bank of Scotland's first banknotes is said to have been made.
As a result of a Lifespan e news letter campaign in the autumn of last year we received an enquiry from the Mott MacDonald team in Edinburgh.

After several on line meetings and an on site visit we developed a solution for the Client Edinburgh City Council and introduced CRL Scotland to the project team as a specialist contractor that was capable of delivering the project.

Following a tender process in early 2023 CRL Scotland were awarded the project valued at circa £250,000 as reported in March of this year

The objective of the project was to provide a replacement deck for the existing Colinton Dell Rustic Footbridge with a design life of 120 years. The existing timber deck on the footbridge was in very poor condition and a new Lifespan Structures (FRP) deck was designed, manufactured & installed by CRL Scotland as a replacement so that the bridge can be re-opened in July of this year

Due to the very challenging location of the site the CRL team came up with a carefully thought out plan as to how they would remove the old bridge and be able to safely install the new Lifespan FRP deck sections.

Additional challenges for the team included a high pressure gas main adjacent to the existing bridge, the steepness of the Dell either side of the bridge location and that everything had to come through the famous Colinton Dell Tunnel.

The new Lifespan Structures FRP deck was designed in house to conform with a specification provided by Mott MacDonald. The new deck of approximately 28m span was supplied in 5 sections of 5.7m long x 2.5m wide and 65mm thick that are mechanically fixed onto the existing longitudinal steel beams, that are in good condition. A new 1.5m high galvanised steel parapet was also be installed.

Watch the video here of the completed bridge
https://youtu.be/7F7L-bdyUPE

Due to economic & climate considerations Clients demand ever more sustainable options when trying to repair or extend the life of their bridges rather than its complete replacement. Bridges often require repairs and eventually wholescale replacement of key structural elements during its service life & these can be very expensive and disruptive to the users of the bridge. Perhaps the most disruptive and costly is that of the deck replacement which could be steel, concrete or a timber deck for pedestrians, cyclists and vehicle trafficking.

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The extent to which manufacturing-induced fibre mat misalignments compromise the structural integrity of pultruded GFRP road bridge decks is not properly understood. The problem is often critical at the web-flange junctions, which frequently contain the most severe misalignments and are subjected to high local moment-shear (M-V) combinations due to concentrated tyre load and also global vehicle load effects. Over the last 20 years, several GFRP decks have developed tyre load-induced damage of the top flange, due in large part to the prevalence of fibre misalignments.

Colinton Dell is a steep-sided gorge and wildlife refuge on the Water of Leith, just north of the old village of Colinton on the outskirts of Edinburgh. It extends from Colinton Parish Church towards Slateford along the Water of Leith Walkway and has an area of 10 ha (25 acres). The Dell includes mature and ancient mixed woodland and the protection afforded by the high banks and thick undergrowth makes it a natural habitat for wildlife, including numerous bird species and amphibians, voles, weasels, stoats and occasionally roe deer.

As 2022 continues to be an extremely busy time for Lifespan Structures we are pleased to announce that Steven Dunn has recently joined to further strengthen our specialist team. A civil engineer with over 25 years of experience in providing technical and commercial support to Clients, specifiers and contractors he has strong knowledge in specialist areas including structural concrete repair, structural strengthening utilising carbon fibre plate (CFRP), composites, adhesives & ultra-high modulus plates.

Working together with our sister company Concrete Repairs Limited, and our various other supply chain partners, a new 12.5m by 3.0m wide bridge has been installed. Initially Lifespan Structures were originally commissioned to produce an outline design to allow the Client to carry out the necessary consultation with the relevant statutory bodies, and subsequently develop this to a detailed design ready for the construction phase. The Client’s framework contractor employed Concrete Repairs Ltd to carry out the installation of the new bridge, including new foundations, lifting operations and attachment of parapet.

Bridge decks often require repairs and eventually replacement during the service life of a bridge. These can be steel, concrete or timber decks for pedestrian and vehicle access. At Lifespan we can design, supply, and if required install, lightweight FRP composite decks which can reduce the deck dead load by 50%. These decks reduce the environmental impact in terms of carbon and energy embodiment. They are also quicker and safer to install compared to traditional materials. The decks are delivered complete with surfacing and ready for installation onsite.

Information on the design of FRP footbridges has developed quickly over the last few years, with the new version of the DMRB which included the publication of CD368 - Design of fibre reinforced polymer bridges and highway structures, and the updates to recommendations in Europe such as CROW-CUR recommendation 96-2019 Fibre-reinforced polymers in buildings and civil engineering structures (CUR96)
Whilst CD368 is now very much in line with CUR96, there are still some fundamental differences between the 2 documents.

Off site production allowed us to continue with this project during the lock down.  Once restrictions were eased the existing bridge was removed and the foundations upgraded by CRL working for Kent Highways, before the new bridge was installed in June. KCC Cabinet Member for Highways and Transport, and Member for Tonbridge, Michael Payne said:
“This work was carried out to provide a strengthened and refurbished bridge to ensure it continues to be safe river crossing for the public to use. “The original deck was made from railway rails with a type of expanded metal mesh reinforcement, but unfortunately it wasn’t able to handle the number of people using it.