CEMENT: When mixed with water it hardens and turns into paste because of the hydration reactions and processes. It is an inorganic and finely ground hydraulic binder that preserves its resistance and stability even under water. In fact, cement is defined as a hydraulic binding material obtained by grinding the mixture of natural limestone and clay after being heated to a high temperature. The hydraulic binding substances form a rigid mass when reacted with water and then they do not dissolve in water, preserve or even increase the rigidity and resistance.