If you wanted to build a house, what materials would you use? When a country is newly settled, wood is available. But after many trees are cut down, wood becomes more scarce and expensive. Wood also catches fire easily. As a country becomes more densely settled, people live closer together in cities. Stone and brick replace wood as building materials.
Large cities ban wooden houses in the urban center, and sometimes they even ban wooden shingles. In their place, concrete or cement houses have been built.
Our grandfathers would have been shocked at the idea of a house built of sand. They would have worried that every rainfall might make their homes melt away. Even after thousands of concrete buildings were in use, many people still feared that they would not stand the cold winters and hot summers of the United States. But it has been proved that concrete is a success provided it is properly made.
Concrete has been used for many purposes besides building, and the number of purposes increases rapidly. It’s used for blackboards, refrigerator linings, and railroad ties, as well as for poles or posts of all sizes.
Concrete that is carelessly made is very poor stuff and dangerous to use. It is not at all reliable and may give out at any time. But concrete made of the best materials and properly put together can serve many purposes.