Which of the following lists the standard concrete ingredients?

• A. Rebar, cement, sand, gravel
• B. Water, cement, sand, gravel
• C. Portland cement, coarse aggregate, fine aggregate, water
• D. Asphalt, aggregate, water

Answer: (C)

Concrete is made from a binding material, aggregates, and water. The binding material is Portland cement, which reacts with water in a chemical process called hydration to form a hard matrix. The aggregates provide bulk, strength, and dimensional stability, coming in two sizes: coarse and fine. Water activates the cement so the mixture can be worked before it sets.

So the standard concrete ingredients are Portland cement, coarse aggregate, fine aggregate, and water. The other options mix in things that aren’t part of the basic concrete mix (rebar is reinforcement, asphalt is used for asphalt concrete, and while water and cement are essential, naming Portland cement plus the two aggregate sizes gives the precise, standard list).