Reuse of harbour and river dredged sediments in adobe bricks

International audienceDredged sediments from ports and rivers are treated as waste material. The disposal of waste sediments has environmental concerns and requires financial resources. Dredged sediments reuse in building material such as adobe bricks can provide an alternate solution to valorize and handle this waste material. Adobe bricks are eco-friendly construction materials manufactured with clayey soil and fibers. Natural fibers addition improves mechanical and thermal characteristics of adobe bricks.In this research, a pilot study was conducted to manufacture adobe bricks from harbor dredged sediments and replicate the procedure to manufacture adobe bricks for river dredged sediments. Harbor sediments were taken from Dunkirk port, France. The physical and chemical characteristics of these sediments were analyzed. Sediments suitability for adobe bricks with grains size and Atterberg limit was discussed with different approaches. Bricks were manufactured by mixing Dunkirk sediments and saturated hemp shiv at different hemp shiv content. Sediments and fibers were mixed with a mortar mixer and molded into specimens of 4*4*16 cm3. Dynamic compaction was opted to compact the bricks. Drying of bricks was done in the oven at 40 °C. Finally, sediments mixing, molding and compaction procedures were derived and problems encountered during were discussed.The procedure derived from Dunkirk sediments was implemented on Usumacinta River sediments to make adobe bricks with the addition of palm oil flower fibers (POFl). Characteristics of Usumacinta River sediments and palm oil flower fibers were found to use in adobe bricks. Palm oil flowers fibers were cut with a knife mill of grid-2 cm and grid-3 cm. Dunkirk sediments bricks manufacturing process was repeated to make bricks from Usumacinta sediments.Laboratory scale manufacturing and testing of bricks from Dunkirk port sediments and Usumacinta River sediments allows to observe the valorization of dredged sediments in adobe bricks with mechanical perspectives. In this study, properties of bricks manufactured by both harbor and river dredged sediments such as tensile strength, toughness and fibers distribution inside the bricks were studied and compared