Which materials are defined as cementitious?

Cementitious materials are those that have the property of setting and hardening when mixed with water, leading to the formation of a solid mass. Among these materials, Portland cement is a primary component, but the definition also extends to various additives and supplementary materials that can improve the properties of the resulting concrete or mortar.

The inclusion of other additives alongside Portland cement expands the range of cementitious materials. Common additives can include fly ash, silica fume, and slag, which enhance durability, workability, and resistance to certain environmental conditions. These materials, when combined with Portland cement, contribute to the overall performance and strength of concrete, allowing for greater versatility in construction.

Hydraulic cements, which set in the presence of water, are a subset of cementitious materials but do not encompass the full range available in construction applications. The same goes for gypsum and sand; while they can contribute to the composition of different building materials, they are not typically classified solely as cementitious.

Thus, considering the wider context of what can be combined with Portland cement to create effective building materials, the definition of cementitious encompasses Portland cement and various other additives that enhance performance.