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STRUCTURES & INFRASTRUCTURE
RONNIE TURNER
W
hether its concrete repair, rail fixing, chemical anchoring or bridge strengthening, most jobs on our rail network have to be done in possessions, putting a great deal of stress on the design and installation team to ensure works are completed effectively and within strict timescales. A major consideration for any solution is the curing time needed before the return to service, which is usually non-negotiable. However, new technologies have been created to ‘supercharge’ installation works after extensive research and development.
Repair challenges Usually, polyurethane, polyester and epoxy resins are specified for track repairs, whether its direct fixation or fixation to concrete or wood. They need several hours’ curing time. And when sound-reduction solutions are needed in underground systems or built-up areas, a new acoustic product comprising a sponge-like polyurethane grout can be used. Sika, a speciality chemicals company, can supply a report to demonstrate dBA output levels before and after installation. From restoring the lifespan of platform harp units to strengthening bridges, any concrete asset can be repaired with expert input. The old adage that ‘prevention is better than cure’ has never been truer in respect of overloaded structures and modern solutions can deliver repairs quickly, with little disruption. New carbon fibre materials such as FRP can reinforce bridges with minimal disruption, providing a thin section solution - as little as 1.2mm - compared with steel or encased concrete which can add much unnecessary dead load to the deck. In order to drive efficiency, Sika has created a new carbo heater unit to reduce adhesive curing time by 80%.
Rail Engineer | Issue 189 | Mar-Apr 2021
Specification and design solutions Whether appointed through a framework contractor or directly by a client, Sika will undertake a site visit to assess the problems and involve other engineering support as required. They will develop a remedy and appropriate specification, all whilst allowing for a fast return to service. Specifications will always include all elements of the works to be undertaken - planning, delivery, installation and curing time - and are developed in conjunction with the client. Regardless of the scale and the scope of the tasks at hand, working with experts schooled with the understanding, knowledge and expertise to recommend the best solution is invaluable; they could be the difference between a happy client and a hefty cost overrun bill.
SARAH LANGLEY
Waterproofing Rail refurbishment works aren’t always on or above the tracks though; there is also demand for below-ground schemes, particularly those that need waterproofing. Regardless of whether it’s a repair or new-build project for a station or tunnel, infrastructure needs to be effectively protected from water ingress. There may also be times when additional protection is required from gases - particularly deadly ones such as radon - that can penetrate below-ground structures and subsequently threaten those inside them. Correct planning and involvement of a knowledgeable design team early on can ensure the specification is fit for purpose.
