What is the purpose of assigning exposure classes to concrete?

Assigning exposure classes to concrete is primarily aimed at evaluating its durability against specific environmental conditions. Different exposure classes take into account factors such as moisture, temperature variations, the presence of chemicals (like chlorides), and freeze-thaw cycles. By categorizing concrete based on its intended exposure, engineers can select appropriate concrete mix designs, additives, and protective measures to ensure that the structures remain resilient and long-lasting in their specific environments.

The other options, while relevant to different aspects of concrete or construction, do not specifically pertain to the primary intent of exposure classes. Aesthetic properties relate to how the concrete appears, which is not the goal of exposure classification. Load-bearing capacity is more about structural integrity under weight and does not inherently consider environmental effects. Classifying concrete as structural or non-structural deals with its intended use rather than its durability under various exposure conditions.