M25 EMI Waterproofing

Constructing Excellence

Connect Plus holds the 30 year DBFO (Design Build Finance Operate) Contract to manage the M25 network for Highways England. The motorway, which is one of the busiest in the UK requires constant maintenance to ensure traffic can flow around the capital.
By its very nature, the 30 year DBFO contract encourages Connect Plus and its supply chain to design maintenance and repair solutions with whole live cost and value in mind, and Connect Plus is incentivized through a penalty charge system, PayMec, to keep interventions on the network to a minimum.
Over the past year, the M25 EMI (Enhanced Maintenance Intervention) Waterproofing team has been responsible for managing surfacing and waterproofing defects across the entire M25 network in a more proactive way, planning defect repairs in clusters, and adopting new working methods to ensure the best value for the client.
Previously, the challenge with this type of maintenance has been that defects were addressed in a reactive way. For example, after a period of heavy rainfall, a pothole formed in the road surface causing a lane to be closed, triggering an emergency repair to re-open the lane. Under these circumstances, the immediate defect would be dealt with, but due to the emergency nature, the rest of the structure wouldn’t be fully assessed, which would result in repeat visits to the same area of the network.
Whilst emergency repairs will always be required, the M25 EMI Waterproofing team have implemented a new strategy for identifying and repairing defects more efficiently.
Using existing technology in news ways, we’ve used Ground Penetrating Radar surveys to identify moisture content in the surfacing and waterproofing layers of the structure deck. These surveys produce detailed visuals of the surface conditions on the structure, and highlight weak points which aren’t always identified by the naked eye.
This allows us to deliver more for less, tackling repairs in clusters, resulting in fewer interventions on the network, and reducing disruption to motorists and workforce exposure to live traffic.
In 2018 we completed eight separate EMI waterproofing schemes totaling £1.5m in value, treating 1500sq metres of defective or degrading waterproofing and surfacing.