Asphalt joint inside and outside the tunnel
The part of the asphalt joint inside and outside the tunnel was constructed in two phases. Some of the work was carried out at the weekend so that on Monday, the asphalt team could work on the surface layer.
The work inside the tunnel was complex. Each section of the Velser tunnel is 768 metres long, which means that a total length of more than 3 kilometres of bitumen tape asphalt joint had to be applied. It would have taken an extremely long time and been extremely labour-intensive to do that by hand, hence the suggestion to use a TOKOMAT® machine to do the job, despite the obstacles in the tunnel.
Maurice: “The drainage holes in the barrier at 2-metre intervals were a complication. Would the TOK® tape stay stuck down if you could only apply it in such small pieces? How were we going to cover such a long distance without having to stop every 2 metres? The project presented quite a challenge…”
Would the machine be able to cope with those drainage holes in the barriers? Could the TOKOMAT® machine complete the job in one go, without having to stop at every drainage hole? If it kept having to stop, it would take a lot longer and you would keep having to start off again and work out where to start from.
The solution: work together on smart solutions
The time pressure on the renovation of the asphalt and the unique situation of the tunnel called for a creative solution. Maurice came up with a technical solution: an additional support wheel that would run against the wall instead of just having one wheel on the ground. This would enable the nozzle (that applies the bitumen tape) to be kept in a constant position.
We teamed up with the customer and got going on the job: while the machine was in operation, workmen cut away the surplus bitumen material that had been applied over the holes. By working in this way, the TOKOMAT® machine was able to complete the whole job in one go.
“Things were tense when we started the job… no-one knew whether it was actually going to work! After the first 10 metres, everyone was able to breathe a sigh of relief: the method was working! It was a fine example of successful collaboration. I had adapted Imbema’s machine in such a way that the TOKOMAT® machine was able to remain stable, even when it had to pass over the holes,” explains Maurice.