Mechanical properties of waterwork sludges – shear strength

In order to ensure a regular and environmentally safe utilization and disposal of waterwork sludges especially the mechanical properties must be controlled. Monitoring of the mechanical properties is of great importance to almost all treatment, utilization and disposal operations. Depending on the raw water source and the treatment processes, different types of waterwork sludge can be described. The first step of this research project included the collection of data from literature reports, information about measuring methods on rheological and soil mechanical parameters and preliminary measurements on selected waterwork sludge samples. Measurement of vane shear strength is a method used in the field of waste disposal/landfill in Germany. Therefore this method was the main topic of the first investigations. Aims were to examine: 1. Influence of water contents and dewatering capacity on shear strength. 2. Correlation between laboratory and field measurement devices. Sludge samples from different waterworks were investigated with following devices: laboratory vane shear apparatus, pocket vane apparatus, pocket penetrometer and capillary suction time measuring.