In construction? Concrete is a building material made from sand?, water, and limestone that in a mostly liquid form and that eventually dries out into a stone. Concrete was invented in the Roman Empire, but the knowledge of its making was lost, to be reinvented only in modern times. |
In construction? Concrete is a building material made from sand? or other small stones, water, and cement. After mixing the cement hydrates and eventually dries out into a stone. Concrete was invented in the Roman Empire, but the knowledge of its making was lost, to be reinvented only in modern times. |
See particular; individual; abstract.