Co-valorization of marine sediments and construction & demolition wastes through alkali activation

In the present experimental study, the co-valorization potential of marine sediments and construction & demolition wastes (C&D wastes) through alkali activation is investigated. Specimens were produced by mixing raw materials, namely marine sediments and C&D waste components (tiles, bricks and concrete) with the activating solution consisting of KOH and sodium silicate solution. The produced specimens were then subjected to compressive strength testing. The effect of the molarity of the alkaline activating solution as well as the percentage of each waste in the initial mixture on the compressive strength of the final products was also assessed. Also, the effect of high temperature heating (400-800 °C), immersion in water or seawater and subjection to freeze-thaw cycles on the structural integrity of the produced specimens was investigated. Analytical techniques, namely X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were used for the identification of the morphology and structure of the final products.