**6. Sustainable concrete**

Mortar and concrete can have various properties and applications according to the type of cement used and the other components of fine and large aggregates.

The future of concrete research and engineering is trending towards employing waste materials. These wastes, which can be hazardous and difficult to dispose of, may be present in large quantities in the environment [35].

Employing waste in concrete can be achieved by adding it or using it to replace one of the other components, which can achieve or even improve desired properties.
