What physical property of aggregates affects the workability of concrete?

The workability of concrete is significantly influenced by the texture of the aggregates used in the mix. A rough or angular texture can increase the surface area of the aggregates and create more friction between them, which can make the concrete mix more difficult to handle and place. In contrast, smooth and rounded aggregates allow for better flow and less friction, enhancing the workability. This property is essential for achieving a uniform consistency in the concrete, making it easier to manipulate during mixing, pouring, and finishing processes.

While other factors such as moisture content can also impact workability — for example, excessive moisture can lead to segregation or bleeding — the primary physical property related to the texture directly influences how the aggregates interact within the concrete matrix. This is particularly important in ensuring that the concrete can be compacted properly, which affects the final strength and durability of the structure. Color and weight, while they may have some influence on various aspects of concrete behavior, do not directly affect workability to the same extent as texture does.