While the terms are sometimes used interchangeably, concrete and cement are not the same. Concrete is a building material and composite of aggregates, including sand, gravel, cement, water, and other materials. Cement is just one ingredient of concrete, but it’s a key ingredient, typically making up 10-12% of the volume.
Astonishingly, a small portion of precast concrete is cement. A fine powder that’s usually gray or white, cement is hydraulic, meaning it chemically reacts with water. As the concrete components mix, cement helps turn the mixture into a flowable, formable emulsion, binding the components as the concrete cures into a rock-like substance used for everything from simple sidewalks to sophisticated skyscrapers.