Portland concrete, the main ingredient of concrete, which is strictly controlled by the chemical compound of calcium, silicon, aluminum, iron and small amounts of other ingredients to which gypsum is added to the final grinding process to regulate the setting time of concrete. Lime and silica make up about 85% by weight. Among the materials used in its production of limestone, shells, chalk and marl or in combination with shale, clay, slate or blast furnace slag, silica sand, and iron for the production Read more [...]