A solidification method by cement of dredged sludge has been performed in laboratory during last four years. The treated sludge is partially contaminated by some heavy metals. The objectives of the research program was to treat and reuse the solidified sludge as road or civil construction materials. First to evaluate the mechanical performances of the obtained geomaterials, axial compressive tests have been run on cylindrical samples taking into account the percentage of cement and additives, the type of storage, the initial water content of the sludge. The environmental performances are obtained with leaching tests on samples which are broken or not in relation with the rate of heavy metals contaminants, the porosity and the ingredient materials. This paper gives the main results from the analysis of the mechanical and environmental tests. They are mainly the relationships between the mechanical, physical and environmental properties.
The maintenance of maritime trade and commerce activities includes the dredging operations in the harbors and the fluvial and estuarine areas. The resulting volume of dredged matters pose problems to the harbor managers which are confronted to the environmental recommendations issued from the French and / or European administrations. In fact, the solutions are depended on the quality of the dredged sludge. In the absence of contaminants, different processes are usually applied such as the deposit at sea by immersion, the deposit as embankments, the disposal inside the discharges or quarries, the landfilling or landfarming. When the level of contaminants becomes significant the above processes are not allowed. Alternative solutions are proposed but they need environmental checking for the long term behavior and safety. For low level contamination special discharges are possible with the agreement of the national environment authority. In the case of the contaminated sludge.
