What Is in Concrete?
Concrete combines cement, water, fine aggregate such as sand, and coarse aggregate such as stone. Other materials and admixtures may be included to meet the project's requirements. Cement and water react to bind the mixture together.
Why the Mixture Matters
A mixture is selected for its intended use and exposure. A decorative patio and a surface carrying industrial vehicles can have different requirements. Strength is one consideration; workability, durability, finishing, and curing also matter.
A Useful Question to Ask
Ask what concrete mixture is specified for your project and why it suits the work. Avoid choosing a mixture by a single number or by how quickly its surface looks dry.
Cement is an ingredient. Concrete is the material you build with.
Further Reading
American Cement Association — Cement & Concrete FAQGeneral education for project planning. Your site's conditions and project requirements determine the construction details.