Question: what ingredients are used to make concrete?
Answer: Concrete is a mixture of cement, air, water, sand, and gravel–it's as simple as that! Not exactly. The typical concrete mix is made up of roughly 10% cement, 20% air and water, 30% sand, and 40% gravel. This is called the 10-20-30-40 Rule–though proportions may vary depending on the type of cement and other factors.