Which type of concrete provides moderate sulfate resistance?

Type II concrete is specifically designed to provide moderate sulfate resistance, making it suitable for use in environments where sulfate attack is a concern, such as in soils or groundwater that contain sulfates. This type of concrete typically contains less tricalcium aluminate (C3A) compared to Type I concrete, which enhances its resistance to sulfate.

In contrast, Type I concrete is general-purpose and does not offer any specific resistance to sulfates. Type III concrete is high early strength concrete, which also does not emphasize sulfate resistance but instead focuses on achieving strength more quickly. Type IV is known for low heat of hydration and is typically used in mass concrete applications; it is not primarily intended for sulfate resistance.

Thus, the designation of Type II concrete as providing moderate sulfate resistance is key for applications where such conditions are anticipated, allowing for improved durability and longevity of concrete structures in those environments.