Synthesis of geopolymers based on dredged sediment in calcined and uncalcined states

Abstract The aim of this work is the synthesis of geopolymers from dredged sediments in calcined and uncalcined states. Different amounts of dredged sediments (0, 5, 10, 15 and 20 wt%) were introduced within geopolymers paste. Investigations show that dredging sediments were mainly composed by calcite, muscovite and kaolinite. It was demonstrated that highest compressive strength of 22 MPa and durability in hydrochloric acid solution of the geopolymers were obtained when 15 wt% of calcined dredging sediment were added, this is due to more stable geopolymer matrix. In the other hand, calcination activates dredged sediment by changing its crystallinity into an amorphous structure of higher reactivity in alkaline solution.