Scaling in concrete usually happens when which type of concrete is utilized?

Scaling in concrete primarily occurs when non-air-entrained concrete is used. Non-air-entrained concrete lacks the microscopic air bubbles that help provide resilience against freeze-thaw cycles. When water within the concrete freezes, it expands, and without these air pockets to cushion the expansion, the surface can crack, pop, or flake off, resulting in scaling.

On the other hand, air-entrained concrete is specifically formulated with air bubbles that enhance the concrete's resistance to freezing and thawing conditions, minimizing the risk of scaling. High-strength concrete and lightweight concrete also have their own unique properties and applications, but they do not inherently lead to the same scaling problems associated with non-air-entrained varieties. Thus, using air-entrained concrete is critical in environments susceptible to harsh weather to prevent scaling and ensure the durability of the concrete structure.