Leaching in the context of cement and concrete refers to the process by which water-soluble compounds are dissolved and removed from the material due to the interaction with water. This can include ions such as calcium, sodium, potassium, and other chemical elements that are part of the cement matrix. Leaching is a critical concern in the durability and structural integrity of concrete structures, particularly in environments with high moisture levels or submerged in water, such as marine structures or underground foundations. The removal of these elements can lead to a reduction in mass, changes in microstructure, and ultimately, a decrease in mechanical properties.