In concrete mixing, which component follows cement, sand, and coarse aggregate?

• A. Water
• B. Lime
• C. Air
• D. Pigment

Answer: (A)

Water is added after the dry ingredients because it hydrates the cement, turning the dry mix of cement, sand, and coarse aggregate into a cohesive paste that binds the particles together. The hydration reaction between cement and water creates compounds that give concrete its strength, so the right amount of water is essential: enough to wet and coat all particles for workable consistency, but not so much that excess water creates voids and weakens the final product. Lime belongs to older lime-mortar systems, not modern concrete. Air may be present and can influence durability, but it is not a primary binding component. Pigment adds color and does not contribute to strength.