Shaft-in-Shaft Rehabilitation & Shaft Renovation

The advantage of HOBAS ShaftLine Products is the minimal loss in cross-section, for they are not only relatively light walled, they moreover can be produced at variable lengths and with a wide range of diameters. Consequently, the cross section is reduced by only a few millimeters. The one-piece seamless CC-GRP Shafts are suitable for very deep structures as well. Due to their low weight, they can be installed with the help of light construction equipment only, which is an important point regarding cost saving. A further advantage of HOBAS Shaft-in-Shaft Systems is that the GRP Shaft Channels need no sub-form. This ensures a trouble free implementation of all required radii and bends for the connections. The gap between the new shaft and existing pipes is bridged using small pipe segments which are permanently fitted and sealed with GRP laminate without creating ridges in the channels. In the end, the laminate is once again completely sealed, the annulus is filled with liquid concrete mortar and the shaft’s superstructure is restored. The concrete cone which in this project was supplied by a local builders’ merchant, is sealed with laminate to ensure corrosion resistance.