What aspect does 'soundness' describe in relation to aggregates?

In the context of aggregates, 'soundness' primarily refers to their resistance to weathering, which is essential for determining how well the aggregates can maintain their integrity after exposure to environmental conditions. Sound aggregates will not deteriorate or break down significantly due to factors such as freeze-thaw cycles, chemical actions, or other weathering processes. This characteristic is crucial for ensuring the longevity and durability of concrete structures.

While resistance to wearing, which pertains to how well aggregates can withstand mechanical wear during handling and in concrete applications, is an important property, it is not what 'soundness' specifically describes. The focus on soundness emphasizes the aggregates' ability to endure external environmental factors rather than just physical wear. Understanding this distinction is essential for assessing the overall quality and performance of aggregates used in construction materials.