Rapid Set repair concretes, based on Calcium Sulfo-Aluminate (CSA) cement, can achieve high strengths in 18 to 24 hours rather than the normal 3 days – a 75% reduction. This provides great benefit in programme betterment and also reduces worker exposure on a live network and customer impact.
Area 9 looked to use the product on heavily trafficked sections of the Midland Links Motorway Viaduct to gain programme benefits as any traffic management within this vicinity adversely impacts upon Highways England and adjoining Local Highway Authorities network.
A Departure was required and approval for use agreed with SES. Site trials were carried out to ensure that CSA concrete could be placed to achieve successful bridge deck repairs. The use of this new material can save 2 days for every concrete repair stage. Although these new concrete repair products have a cost premium, this is more than outweighed by the reductions in scheme duration, road user disruption and road worker exposure to live lanes.
Traditional concrete repair materials require 3 days curing after placing, in order for it to attain strength -clearly not achievable on highly trafficked sections of motorway. The weekend delivery model resulted in an 18-21 hour window whereby concrete repairs had to be undertaken and cured in time to complete follow on activities and return the network back to service in time for the Monday morning. The use of the rapid set materials afforded us this opportunity as they are able to achieve the required strengths in the 24 hour window. We utilised full weekend lane closures to carry out the repairs and were able to resurface and open the lane fully for the Monday morning peak. A great result