What does gradation determine?

Gradation refers to the distribution of particle sizes within a given aggregate. It plays a critical role in determining the concrete's strength and workability. When the gradation is well-balanced, it ensures that there are a range of sizes present, which helps fill voids between larger particles with smaller ones. This optimal packing arrangement can lead to improved strength characteristics because it allows the concrete mix to achieve a tighter, denser structure. Furthermore, the right gradation impacts workability as it allows for better flow and easier handling of the concrete, which is essential for achieving a consistent mix.

While other factors contribute to concrete strength and workability, gradation is a fundamental aspect that influences both, making this option the most appropriate answer. In contrast, weight measurement, color, and aggregate size classifications do not directly address the effects of particle size distribution on concrete properties.