Valorization of Raw Materials Based on Fly Ash of Eggshells and Algerian Sand Dune (Southern West of Algeria) for Synthesis of Environmentally Cementitious Materials: Synthesis and Characterization

The dominant cementitious materials based on fly ash are attracting attention in the global research community because of their properties that affect their performance such durability, mechanical properties, physical–chemical properties and reduction of carbon dioxide. The present study relates to an economical and environmentally method, capable of being implemented in 2 simple steps. Method of preparing new green cementitious material based on eggshells rich in calcium (Ca) and sand dune (southern of Algeria) rich in silica (SiO₂). The first step of preparing SiO₂ from sand include sand obtained with size less than 100 microns by washing with an alkali and hydrochloric acid (HCl) followed by washing with distilled water. The sand particles are then dried at room temperature. Further, the second step includes a preparation of fly ash of eggshells with particles size in a range of 100–120 microns. The method includes mixing the silicon dioxide and fly ash particles in predefined ratio, heating the mixture at a temperature for predefined time. Cementitious material was finally obtained. The optimal mix has a compressive strength of 49.71 Mpa, is the most flexible (E = 2.63 GPa and ductile (εr = 65.42%).The chemical and physical properties of the prepared cementitious material were analyzed by several technics such as XRF, XRD and SEM.