Manhole renewal

Aarsleff Pipe Technologies’ method for No-Dig manhole renewal is both efficient and flexible. Among other things, it ensures a long life and a sound financial base.
We use jetcrete. We have developed and refined this method, and consequently, we are able to carry out manhole renewals quickly, efficiently and without significant inconvenience to the surroundings. We use the method for renewal of manholes from DN500 to DN1250 in a depth of up to 10 metres.

When renewing manholes, we always make sure that they are cleaned and that water infiltration, if any, has been sealed. Upon request of the client, we also remove the step irons. If there are major holes in the existing manhole structure, we repair them. Inlets, if any, are blocked temporarily. We also measure the strength of the existing manhole wall carefully so that we can determine the layer thickness of the jetcrete. We can apply thicknesses of up to 40 mm in the same process.

We carry out the application of jetcrete by lowering a specially developed spray head down into the manhole from a rack hanging above the manhole. It is very important to centre the spray head above the centre of the manhole. When the spray head has been placed correctly, one of our operators lifts it up and lowers it manually until the manhole wall has reached the required wall thickness.

Aarsleff Pipe Technologies always ends a manhole renewal by checking that we have reached the required wall thickness. As part of the final completion of a manhole renewal, we smooth and rough-cast inlets and outlets, clean step irons and re-open blocked inlets, if any.