Work at night in Randers

In 2009, Aarsleff Pipe Technologies carried out two big manhole renewal projects for Randers Spildevand A/S (wastewater company). Both projects comprised manholes placed in areas with much traffic. As always, we wanted to minimise the inconvenience to road-users, and consequently, we carried out part of the renewal work at night. A great part of the night work was focused on manholes placed in crossings with traffic lights.

One of the two renewal projects comprised renewal of 14 1 m manholes with the concrete type KS2B in the area around the road Clausholmvej in the southeast part of Randers. The manholes were part of a DN600 wastewater pipe. The manholes were in a very bad shape, due to hydrogen sulphide attacks. Actually, the manhole walls were almost disappearing and thus, the risk was high that the manholes would collapse and block the pipe. It was very likely that an urgent excavation of the pipe, resulting in big economic costs and traffic problems, would have been necessary.

We renewed the 14 manholes in only 3 days by applying approx. 15 mm jetcrete so that the manholes got their original strength back. We removed the step irons in all manholes and completed the work with bricklaying of benches.

The other manhole renewal project comprised renewal of 11 1 metre manholes with the concrete type KS2B in the area around the road of Oust Møllevej in the northeast part of Randers. We carried out the manhole renewal project as part of the work by renewing a DN300 wastewater pipe which was very damaged by hydrogen sulphide. It was very important to include the manholes in the project as, by only renewing the pipe, we would only move the hydrogen sulphide problem to the manholes over time. The renewal which only lasted two days was thus an important part of the work with ensuring a tight pipe system in the future.