Christmas Presence
In the manhole reinstatement industry where re-failures are almost as common as manholes themselves, we were promising a real revolution. This was our chance to prove it.
We'd started with a Mastic Asphalt product that is exceptionally durable, and unlike anything in use in NZ. Designed in the UK, and approved by their Highways Authority for use on all roads, it not only shortens the works time, but significantly lengthens the life of the repair.
And to add to what is in itself an exponentially improved product, we developed a system for neater, faster and stronger repairs.
But until Christmas, this had all been theoretical. Having spent the preceding six weeks at Media Works working on the replacement of their 360m2 car park, fine-tuning our equipment, we now wanted a venue where we could implement some test reinstatements.
A project manager at one of the larger Construction Companies offered us a venue which would be vacant between Christmas and New Year - it was in an industrial park, where the roads were in (to be kind) a pretty shabby state. We had all the time we needed to test and document our procedures. We picked three test scenarios:
A pothole in the open space of the carpark
This was a functional fill. The pavement had breached, and the substrate had started to weaken, but it was relatively easy for us to fix. The procedure involved:
- Cutting away the broken ground. Our circular cutter is perfect for this, as it minimises the size of the repair, and does not leave square edges which invariably create a weak point in the repair.
- Removing the loose material and preparing the hole for fill
- Filling the hole with Neuchatel MWR recycled Car-Park-grade mastic asphalt.
A manhole repair
This was a typical manhole repair, and involved as follows:
- The truck was parked to create a barrier with traffic and pedestrians. Under normal circumstances the worksite would be coned off, but this was unnecessary as the venue was deserted on this day.
- The entire operation was conducted within a couople of metres of the truck, minimising our impact on the area.
- The hole was cut and cleaned.
- Because the rim was sitting directly on the concrete, no spacer layer was needed, saving about 20 minutes off the install time.
- The fill layer was applied stopping about 20mm short of the top of the hole.
- A final layer was applied, and leveled with the road, before sprinkling with sand for extra grip.
A structural repair to the entrance to the building.
This storage facility frequently had forklifts traversing the entranceway, and over time they had broken the asphalt away from the concrete threshhold. This presented a bit of a dilemma, in that we needed to put hot asphalt up under the roller door, without actually opening the door. We dealt with this as follows:
- Cut and excavated around the threshhold to find stable substrate. The resulting hole was between 30mm and 100mm below the pavement level.
- We placed a base layer over the entire extent of the hole, to provide stability for the remainder of the patch.
- We applied a reasonably thick filler layer to the deeper parts of the hole, to ensure that a relatively uniform surface remained for the final layer. This required 20 minutes of work as we had to continue massaging the asphalt to the sloping contour to prevent pooling.
- While we were waiting for the filler coat to break, we attended to the delicate procedure of asphalting under the roller door. This required patience as the gap was small and we did not want the hot asphalt coming in contact with the rubber seal on the door.
- Once all material was laid, we then went back over the job to blend the seams, and ensure a smooth job.
The time-lapse video captures the final layer going on. If you look closely you can see three distinct layers - the base layer; the filler layer in the middle, and; the top layer under the roller door.