When using the curved grooving tool, how much water should be mixed with the soil sample?

When using the curved grooving tool for soil sample testing, the recommended amount of water to be mixed with the soil is crucial for achieving the desired consistency and workability of the sample. The choice of mixing 15-20 mL of water is based on the need to adequately moisten the soil without making it overly saturated, which can affect the test results. Proper moisture content ensures that the soil particles clump together effectively, allowing for accurate assessment of its properties.

Using this specific range of water helps maintain a balance conducive to optimal testing conditions, leading to more reliable results. If too little water is used, the soil may not be workable, while too much could lead to a muddy sample, complicating the testing process and potentially skewing the results.