What type of concrete is used in exposed areas such as porches, driveways, and sidewalks?

• A. Air entrained
• B. Non-air entrained
• C. High-strength
• D. Portland cement

Answer: (A)

Air-entrained concrete is used in exposed areas because the tiny air voids created by an air-entraining agent provide space for water to expand when it freezes. This relief helps prevent internal pressure from causing cracks, spalling, and premature wear on surfaces that endure weather, moisture, and freeze–thaw cycles—like porches, driveways, and sidewalks.

Non-air-entrained concrete lacks those micro air voids, making it more susceptible to cracking in freezing conditions. High-strength concrete focuses on higher compressive strength and isn’t necessary for typical outdoor walkways, and Portland cement is just the binder in concrete rather than a concrete type itself. So the best choice for durability in exterior, exposed areas is air-entrained concrete.