Cement

Cement is a material of concrete and mortar, and is a gray powder that has the property of hardening by a chemical reaction with water. Limestone, clay, silica, and iron oxide are the main raw materials. There are three types: Portland cement, mixed cement, and special cement. Portland cement is the most common in Japan. Cement is rarely used alone, and is mainly used as a repair material and adhesive, such as repairing cracks in concrete and bonding blocks.