The DBFO Company, HMG, had been experiencing problems with recurring failures with a number of their existing manhole covers and frames along the Westlink. The heavy volume of traffic was taking its toll and a long term solution was sought to alleviate the ongoing problem.
UltraCrete, already providing years of technical advice to GRAHAM HMM’s Sustainable and Innovative Development Managers, were approached for the specialist counsel.
UltraCrete recommended the installation of a composite cover installed using materials from their BBA/HAPAS Approved Manhole Reinstatement System, such as Envirobed HA104® high performance bedding mortar, which exceeds HA104 requirements adopted by the Highways Agency, Department of Transport and SROH. It achieves a superior compressive strength of 51N/mm² and a tensile strength of 5.8N/ mm² in just 3 hours, offering significant resistance to heavy trafficking and manhole frame deflection. QC10 F Rapid Strength Flowable Concrete, a two-part fibre modified flowable concrete, was used as the back fill around the manhole frames thus providing a solid reinstatement. The site was surface finished with a hot overlay. Also available as part of UltraCrete’s HAPAS Approved System; UltraCrete SCJ Seal and Tack Coat Spray, which is applied onto vertical edges and the surface base of the reinstatement before the application of asphalt and UltraCrete Instant Road Repair® Cold Lay Asphalt Concrete for first time permanent reinstatements.