Concrete reinforced with steel was first invented in 1850. Because of its limited tensile (ability to stretch or be stretched) strength, concrete would be of little use today if it wasn't reinforced with steel.
Trivia 1995 - World cement production was 1,421 million tonnes. This would be sufficient to make a road around the world 1 m thick and 188 m wide or a 3.5 m square column from the earth to the moon. Associated Sites: |