North Carolina General Contractors Practice Exam

What are the three methods of determining soil density?

1. Proctor test, Capillary test, Sand cone test

2. Proctor test, Gravel test, Nuclear Density test

3. Proctor test, Sand cone test, Nuclear Density test

4. Sand testing, Cone index, Nuclear Density test

The correct answer is: Proctor test, Sand cone test, Nuclear Density test

The three methods of determining soil density include the Proctor test, the Sand cone test, and the Nuclear Density test, which is why this answer is correct. The Proctor test is commonly used to assess the optimum moisture content at which a given soil type will densify to its maximum density. This helps ensure that the soil has enough strength and stability for construction projects. The Sand cone test is another field method used to measure the in-place density of soil. It involves using a calibrated sand cone apparatus, where the volume of sand that fills a hole dug in the soil is measured. This allows for a direct calculation of the soil's density in its natural state. Lastly, the Nuclear Density test utilizes radioactive isotopes to measure the density of the soil. This method provides rapid and accurate results in the field, allowing for immediate assessment of soil density conditions. The other provided options include methods or tests that are either not commonly associated with measuring soil density or do not fit within the standard practices used in civil engineering and construction. For instance, the Gravel test and Cone index do not specifically determine soil density, and Sand testing typically refers to other properties of sand rather than soil density.