EJOT

Road tunnels present a major challenge to metal fastening systems of all kinds given the highly corrosive atmosphere that is present within them. But where mechanical anchoring is concerned, specifiers and engineers can comfortably achieve their performance and durability goals in these demanding environments as a recent project by EJOT UK demonstrates.The installation of the electrical services and public address (PA) system in one of the UK’s most high-profile new road tunnel projects involved the installation of more than 6,000 high performance mechanical anchors.Tasked with providing these anchors was EJOT UK. They supplied EJOT and LIEBIG branded HCR (high corrosion resistance) anchors for the major civil engineering project to BISON UK, who are a nationwide market-leading supplier of fixings, support systems and bracketry to the M&E and building engineering services sectors. Ready-made solutions, ready-made for corrosive environmentsThe company approached EJOT UK for an anchoring solution that could be deployed throughout the new tunnel’s main bore and separate under-tunnel - beneath one of the UK’s most significant waterways - to meet the demanding performance specification required for the highly corrosive environment. At the same time, BISON also sought to ensure the solution would enable the main contractor to keep the project on track and on budget by avoiding the lengthy lead times and high unit costs often associated with such products.EJOT’s UK anchoring team was able to meet the requirements of the brief with maximum efficiency. They recommended two products from its portfolio – the EJOT BA-E Plus HCR through-bolt manufactured in 1.4529 high corrosion resistance stainless steel, and the LIEBIG Superplus BLS-P self-undercutting heavy duty expansion anchor manufactured in A4 stainless steel. Understanding applications demands through dedicated supportThe BA-E Plus 10/10 HCR through-bolt anchors specified have been used to securely attach the bracketry for the electrical system trays throughout the tunnel development. EJOT was able to provide a bespoke version of this versatile 120-minute fire-rated through-bolt which features an additional washer to offset the brackets from the tunnel wall and prevent moisture collecting. A special tool was also supplied by EJOT to enable easier overhead installation of the anchors. Vibration resistance an added benefitBespoke LIEBIG Superplus BLS-P anchors in two different lengths were specified for use in stand-off applications that included speakers and other components associated with the tunnel’s PA system. These anchors met a slightly different brief in that they were also required to demonstrate a high level of vibration resistance resulting from vehicle flow through the tunnel. The PA system bracketry then utilised the anchors two lengths to accommodate the size and shape of the speakers in the context of the tunnel’s curved walls.Bill Browning, Business Development Director at BISON UK, said: “The combination of exhaust emissions from vehicles and the moisture laden air, given the close proximity to the water, demanded anchors with a high degree of corrosion resistance, and it was clear that the EJOT and LIEBIG products recommended by EJOT’s anchoring specialist consultants would achieve the performance specification.“But it was also imperative that these could be provided within relatively short lead times and to a strictly controlled budget, and here the EJOT package met the brief without compromise. The EJOT team provided all the technical data necessary to demonstrate that both the BA-E Plus and Superplus BLS products would perform in-situ, with the added assurance of European Technical Assessments (ETAs), and enable fast, efficient installation.“And because of the way their business is set-up, they could offer the flexibility we required to accommodate the bespoke anchor design and smaller volumes involved in this project.”Both the anchors supplied by EJOT for this tunnel project are designed for use in cracked and non-cracked concrete where only a relatively shallow embedment depth is possible. They provide medium to high load capacity in a diverse range of applications including nuclear facilities and industrial plants.

The design principle of the LIEBIG Superplus BLS range is simply unique. Available in zinc-plated carbon steel and A4 stainless steel, its design offers the high load capacity and reliability of an undercut anchor, with the ease of installation normally associated with an expansion anchor. That means that, unlike any other competing product, the Superplus range does not require the expense of any special drill bits or setting tools. Performance Benefits and Characteristics:Unique automatic self-undercut / mechanical lock anchorVery high load performanceSetting is torque controlled - no special tools requiredMinimal expansion forces allow small spacings and edge distancesM8 – M16, push-through or pre-installation optionsTwo embedment depths per anchor diameterRange includes shallow embedment optionSimplest, quickest and safest solution availableFor static, quasi-static and seismic loadsUKTA approvalETA approval - Option 1 Approved for cracked and non-cracked concreteACI 355 Nuclear Performance StandardZinc Plated for dry indoor and temporary outdoor use Modularity means more kN per £ investedWith modular design at its core, the LIEBIG Superplus BLS range provides engineers and architects with a reliable concrete anchoring solution that balances superior performance with cost. Developed to provide an alternative to concrete anchors that need pre-preparation of the hole using an undercut tool, Superplus BLS is UKTA approved for use in cracked and non-cracked concrete to provide assured high capacity anchoring in a wide variety of applications and conditions. Read more... Modularity means installation simplicityUnlike other undercut anchors, the mechanical design of Superplus BLS means that it does not require an exact hole depth, to achieve a secure fixing. The teeth on the anchor’s innovative sleeve will always engage to deliver a durable mechanical interlock which allows for easier, more efficient working on site with less risk of installer errors.A key benefit of Superplus BLS is its suitability for concrete applications where only a relatively shallow embedment depth is possible. It can also be used in applications with reduced edge distances and anchor spacings, and is available as standard in Zinc plated carbon steel and A4/80 stainless steel, making the anchor suitable for meeting the most demanding environmental conditions. Read more... Modularity means more flexibilityThe range is available in sizes from M8 to M16 and with standard lengths capable of fastening fixture thickness of between 5mm & 300mm. Thanks to its modular design the anchor can be specified in bespoke lengths. This makes it easy to arrive at an anchoring design to suit the application, with anchors manufactured and delivered to site in short lead times. Read more... Modularity means more versatilityPaul Papworth, who is responsible for Specification Sales at EJOT UK said: “LIEBIG Superplus BLS is a unique anchor which allows engineers and architects to think differently about how they approach anchoring into concrete. In addition to providing the best value ‘cost per kilonewton’, the anchor’s performance characteristics, backed by United Kingdom Technical Assessments, are reliably robust – in line with every concrete fixing solution in the LIEBIG range.”“The anchor represents suitability for such a wide range of applications, with the undercut principle around which the anchor is designed, offering that extra level of performance assurance, safety and risk avoidance.”“Part of the EJOT fastening systems portfolio since 2017, LIEBIG has long been the global go-to brand for concrete anchoring, which today benefits from UK manufacture, technical support and customer service. It all adds up to a locally-delivered package that helps project engineers achieve a solution that meets the specification without compromising project timescales and budget.”Superplus BLS is part of a wide range of LIEBIG and EJOT anchoring solutions, which also includes advanced chemical based systems, concrete screws and through-bolts to cater for every type of concrete and solid base application. Read more...