What is the fourth step in conducting a gradation test?

The fourth step in conducting a gradation test is the dry sieve analysis. This step involves placing the material to be tested on a set of sieves arranged in descending order of mesh size. By shaking the sieves, the particles are separated based on their size, allowing for the determination of the distribution of particle sizes within the aggregate sample.

This step is crucial, as it provides essential data on the gradation of the aggregate, which directly affects the performance of the mixture in construction applications. The results obtained from this step can be used to assess compliance with specifications and to optimize the mix design for various engineering purposes.

Preparation, wet sieve analysis, and weight measurement are all important components of the overall gradation testing process, but dry sieve analysis is the key step that visually and quantitatively illustrates the size distribution of the aggregate, making it integral to the understanding of the material's characteristics.