Restoring the Clyde Walkway

Earlier this year, Paths for All was involved in upgrading part of the Clyde Walkway, a section that was last maintained in the late 1980s.

The restoration work improved the walking surface

Following an invitation from Scottish Natural Heritage and South Lanarkshire Council, we viewed and assessed a 1.3km section of the scenic route.

Despite falling into a poor condition, the walkway was still popular with walkers and visitors thanks to spectacular scenery and areas rich in cultural, natural and industrial heritage.

Problems included large muddy areas, water erosion, encroaching vegetation and decaying timber edging.

Paths for All first became aware of the Ecofast™ Ecoproactive™ soil stabilisation process (currently marketed by Mackenzie Construction Ltd. as ‘Smart Surface®’) following its use to rejuvenate a section of existing path on the National Path Demonstration Site at Oatridge College. That work was undertaken in early 2016 and we were impressed by how well the material had performed.

So we were excited when an opportunity arose to use Ecopractive™ product and process to upgrade this 1.3km of the walkway near Blantyre.
The ability to limit importation of quarried aggregate material, by utilising existing path substrate, was an important consideration in choosing this material and construction process however we were also looking to maximise value for money and ensure that any finished surface was ‘fit for purpose’ for many years to come. Steep gradients that couldn’t be re-routed or stepped, future surface damage from motorbikes and restricted resources for ongoing maintenance meant that more traditional path surfacing materials would not have provided an effective solution and tarmac was not an option due to high cost and landscape fit.

Construction phase

For the Ecoproative™ hydraulic powder to be effective, it requires to be thoroughly mixed within a suitable base substrate material which was, in part, a very worn and surface contaminated Type 1 path with significant sections of railway ash to the western half of the route.
Construction typically begins with any surface vegetation being scraped off, to the required width, and arisings landscaped across the adjacent ground. The exposed base is then thoroughly rotovated to a minimum depth of 100mm using specialist equipment shown in the photos. This process ensured that the substrate material is suitably mixed and that any larger aggregate/soil material is crushed to not greater than 40mm in diameter.  Ecoproactive™ latent hydraulic powder is then applied to the surface, at an application rate of 7%, before being fully mixed into the prepared base material using the same multi-pass rotovation process. The resultant mixed material is hand graded to required levels and compacted to refusal using a typical Type 120 ride-on roller, or larger where space allows. Small quantities of mixed aggregate/Ecoproative™ were dry batched as infill to a flight of ramped sleeper steps.
With Ecoproative™ being an hydraulically activated powder, it is necessary to carefully monitor moisture content through the compaction process. The exceptionally dry conditions experienced throughout this construction phase required the application of water to the surface of the mixed and graded base.
To aid the surface finish/aesthetics, a layer of 6mm grit was applied directly to the surface.

Whilst the finished path is now impervious to water, and highly durable, an element of surface water drainage was designed into the project to help keep water off the surface, something that will be of particular value during colder months where water seeping onto the path from adjacent embankments can freeze and make the route treacherous or impassable.

In addition, one of the most attractive and sustainable features of this product is the ability to rejuvenate existing paths without the need to import aggregate however it cannot always be guaranteed and this project did require the importation of about a third the quantity of aggregate normally expected for a more traditional path build.
The result

The completed works extended to the upgrade of over 1.3km of path. On top of this, 780m of open drainage channel was installed, new signs were erected, timber ramped steps constructed and 125m of ramped path re-opened to allow path users to by-pass the steps.