How is cement concrete and glass made..?
Cement is a fine, soft, powdery-type substance. It is made from a mixture of elements that are found in natural materials such as limestone, clay, sand and/or shale. When cement is mixed with water, it can bind sand and gravel into a hard, solid mass called concrete. Cement can be purchased from most building supply stores in bags Did you know? Four essential elements are needed to make cement. They are Calcium, Silicon, Aluminum and Iron. Calcium (which is the main ingredient) can be obtained from limestone, whereas silicon can be obtained from sand and/or clay. Aluminum and iron can be extracted from bauxite and iron ore, and only small amounts are needed. Cement is usually gray. White cement can also be found but it is usually more expensive than gray cement. Cement mixed with water, sand and gravel, forms concrete. Cement mixed with water and sand, forms cement plaster. Cement mixed with water, lime and sand, forms mortar. Cement powder is very, very fine. One kilo (2.2 lbs) contai
