According to ASTM D698, which methods use the 4-inch diameter mold?

In ASTM D698, which is the Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort, the 4-inch diameter mold is specifically utilized in two methods: Method A and Method B.

Method A is intended for testing fine-grained soils, while Method B is designed for coarse-grained soils. Both methods rely on the standard Proctor compaction process to achieve maximum density and optimum moisture content for the material being tested. The consistency and uniformity of the mold size help ensure reliable and repeatable results across different testing scenarios.

Method C, which uses a different size mold, is not applicable here, hence reinforcing that choices involving Method C are incorrect. Thus, the alignment of the 4-inch diameter mold with Methods A and B supports the selection as the correct answer. Understanding the appropriate usage of these molds is critical for proper testing and achieving accurate compaction characteristics as per the ASTM standards.