
With sections of the motorway in need of refurbishment, Metrail employed a resin-stabilisation technology from Germany to provide innovative, cost-effective and time-efficient solutions for renovating the concrete pavement on a five-kilometre stretch of the east-bound carriageway of the M180, returning that stretch of pavement to Class A without completely replacing the running surface of the motorway.
The challenge
Heavy traffic flows, water egress and uneven settlement had taken its toll on the M180, creating voids under sections of the concrete pavement, thus rendering the carriageway unstable, leading to failures. The fix would require enhanced maintenance, including stabilisation, levelling as well as replacement of the existing concrete slabs.
Solution approach
Rather than completely replace the running surface of the motorway, Metrail employed a cost-effective, long-term solution. Our technique: drilling holes into the concrete to inject a highly specialised resin product whose job was twofold. One: dispace any groundwater trapped below the surface. Two: fill in all voids in the sub-formation.
Over 20,000 holes needed to be drilled, which was carried out with either hand-held drilling tools or an automated drill rig. A standard 600 x 600 mm grid pattern was adopted from the edge of each slab, which is equivalent to one hole per 0.4m2.
Facts & Figures
When?
October 2021 to February 2022
Where?
A five-kilometre stretch of the east-bound carriageway of the M180 between Junctions 1 and 3
How?
Injecting resin into over 20,000 holes.
Technology
A two-component silicate resin, which cures to 90% full strength within 15 minutes. Full compressive strength of c.50n/mm2 is achieved
within the hour.
Result
James Fisher Testing Services has now classified the overall stretch of pavement as Class A
Resin-stabilisation technology from Germany
Let’s start with a few facts about our resin product: mixed on-site, the resin was designed for the stabilisation of concrete slabs on high-speed roads in Germany, where most of the critical roads are built using such slabs. The resin has a product life of up to 30 years, good adhesion to the upper concrete slab, excellent penetration and void-filling capability, and can survive under the road much longer than brittle cement-based systems.
Plus, with this technique the road can be reopened to traffic just 15 minutes after application.


Execution
First things first, a contra-flow system was put in place to allow unfettered access to the carriageway. Then, remember those holes we talked about? Packers were mechanically fixed into them and the resin injected at a controlled pressure. This ensures that any cumulated water gets forced out and the voids are filled completely. The process was continuously monitored using geodetic equipment, and upon taking the packers out of the road, any excess resin on the surface was removed.
Maxicrete was employed in the second phase of the project to repair and seal the joints between the slabs.
The result: M180 section back to Class A
With Metrail’s aim to deliver high-quality work with a focus on careful planning to ensure safety, quality and on-time delivery, we are pleased to report that James Fisher Testing Services has now classified the overall stretch of pavement as Class A.
The maintenance provided is also expected to reduce the frequency of roadworks along this busy stretch of the M180.
