Development of a sealing material and robot for automatic socket rehabilitation of grey cast iron pipes in drinking water supply systems

The project DeWaLoP, led by Vienna Water, aims to develop a robot that is able to apply a sealing system to repair the joint sockets of pressure operating water pipes measuring about 1 m in diameter. To do this, a modification of the sealing material for inner surface application will be developed and a complex robot system will be designed to perform various tasks, such as inspecting, cleaning and restoring. Seven commercial sealing materials with a broad spectrum of mechanical and physical properties were tested. For this purpose, a series of tests was carried out to measure tensile strength, bending and adhesion; in addition, dynamic mechanical analyses, differential scanning calorimetry and thermogravimetric analyses were also conducted. A change in the mechanical and physical properties of these materials after water exposure could be observed. Furthermore, the surface preparation and remaining contaminants, e.g. rust, can affect the adhesion properties of the sealant. The plan is to develop a formulation of a matched material based on the results of these tests and the existing knowledge about the behaviour of sealing materials. The proposed in-pipe robot consists of three main subsystems: a control station, a mobile robot (similar to a vehicle) and a maintenance unit with a redevelopment system. An operator controls the movement of the cable-tethered robot system remotely from outside the construction side.