Tsementi

Tsementi is a binding material used in construction, commonly referred to as cement in many languages. It denotes a powder that, when mixed with water, forms a paste that hardens over time, enabling the binding of aggregates to produce concrete or mortar. The most widely used form is Portland cement, though many other cementitious products exist, including blended cements that incorporate supplementary cementitious materials such as fly ash, slag, or silica fume.

Production involves calcining limestone (calcium carbonate) with silica and alumina-containing materials found in clay or shale to form clinker, which is then ground and mixed with small amounts of gypsum to control setting. The resulting powder, cement, reacts with water through hydration to develop strength and binding capacity.

Applications include concrete and mortar in buildings, bridges, roads, and various industrial structures. Cement serves as a binder for aggregates or as a component in grouts and plastering mortars. It is used in a wide range of construction and infrastructure projects worldwide.

Standards and compliance: cement is produced to international and national standards that specify chemical composition, strength class, and performance. Major systems include EN 197 in Europe and ASTM C150 in the United States. Suppliers and producers operate under environmental and safety regulations; cement manufacturing is energy-intensive and a source of CO2 emissions, prompting ongoing research into lower-emission processes and alternative binders.

History: hydraulic cements date to antiquity, with modern Portland cement developed in the 19th century by Joseph Aspdin, who named it by analogy with Portland stone.

Safety: cement dust can irritate eyes and skin; wet cement is caustic. Appropriate PPE and hygiene practices are advised when handling.