In the UK, concrete repairs happen almost every day, at a range of scales from minor repatching jobs to major structural works.
Part of the reason for this is that a lot of Britain’s concrete infrastructure has survived far longer than even many ambitious estimates, with many major trunk roads lasting without major repairs for over five decades.
The combination of high amounts of usage and relatively limited maintenance means that a lot of these repair projects are bigger than normal, and arguably the biggest such repair project ever undertaken on a piece of concrete infrastructure in the UK was undertaken in 2019 on the Oldbury Viaduct.
Located between junctions one and two on the M5, the £100m project involved repairing structural elements underneath the viaduct once surveyors found that the expansion joints and waterproofing had weakened, which led to several reinforcing elements corroding.
As one of the UK’s busiest motorway sections with an average of 120,000 vehicles using the viaduct every day, it was essential to complete the works, but in a way that reduced as much disruption as was feasible across the 1.6km section the repair works were scheduled to take place on.
The work was carried out in three stages, with the southbound carriageway taking priority over the northbound road before the central reservation was finally completed in early 2020.
This first phase on the southbound part of the road took over 13 months to complete, with a contraflow system designed to allow for all four lanes to be repaired at the same time, with other closures happening on roads directly underneath sections of the viaduct.
Such was the scale of the work that the traditional use of 25kg repair mix sacks carried by hand was simply inappropriate, instead replaced with telehandlers carrying 500kg sacks, as well as using hydrodemolition to cut out nearly a mile of unsalvageable concrete.