3. Stabilization with hydraulic binders

3.1 Hydraulically reacting binders: principles of solidification

Alone or mixed with lime or other additives, cements and other pozzolanic reagents are widely used for the solidification-stabilization of solid waste and sludge. In common parlance, the term cement refers to finely ground mineral materials that "set" in the presence of water to form a porous solid after hardening: this is called hydraulic setting and is due to the hydration reactions of cement compounds. Materials obtained in this way retain their strength, even under water. As far back as antiquity, the Romans used mixtures of lime and natural pozzolans (volcanic ashes) or artificial pozzolans (fired and crushed clay bricks) to obtain a cement with which they built great structures of remarkable durability!...