What is the purpose of the gradation curve in aggregate testing?

The purpose of the gradation curve in aggregate testing is to visualize the distribution of particle sizes within a sample of aggregate. This curve represents the percentage of the total aggregate mass that falls within specified size ranges, allowing technicians to assess whether the aggregate meets the required specifications for a given application.

A well-defined gradation is crucial for optimizing the performance of the mixture, as it influences both workability and strength. For instance, a well-graded aggregate can reduce voids between particles, leading to denser and more durable concrete. This aspect makes the gradation curve an essential tool in evaluating the suitability of aggregates for various construction purposes, as it helps identify whether the mix design will yield desired mechanical properties and overall performance in the final product.

The other options, while relevant to different aspects of aggregate testing and performance, do not directly relate to the specific purpose of the gradation curve. The gradation itself does not measure compressive strength, assess thermal properties, or ensure color consistency, as these factors are evaluated through different procedures or criteria.