During sample preparation for the physical test, how should the remaining material be treated?

The correct approach during sample preparation for the physical test involves separating the material into two parts. This process is crucial as it allows for the analysis of different fractions of the aggregate, which may be distinct in their properties, sizes, or other characteristics. By dividing the sample, you can conduct separate tests on each portion, leading to more accurate and reliable results regarding the material's suitability for use in construction.

This method enhances the understanding of how each size fraction behaves under different conditions, which is valuable when determining how to best utilize the aggregate in construction applications such as base layers. Proper separation ensures that any testing subsequently performed reflects the true behavior of the whole aggregate while allowing for a more thorough evaluation of its physical properties.

The other methods mentioned, such as air drying, wet sieving, and crushing, may be part of sample preparation under certain circumstances but do not address the need for separating materials based on size or characteristics, which is essential for comprehensive testing. Each methodology serves specific purposes, but for the context of the question regarding how to handle the remaining material, separating into two parts is the most advantageous approach.