Cementitious materials are substances that can bind other materials together, primarily used in construction. The most common example is Portland cement, which, when mixed with water, forms a paste that hardens over time. These materials are essential for creating strong and durable structures like buildings, bridges, and roads. In addition to Portland cement, other types of cementitious materials include fly ash, slag, and silica fume. These materials can enhance the properties of concrete, such as its strength and resistance to environmental factors. They are often used in combination to improve sustainability and reduce the carbon footprint of construction projects.