Comparison of Fine-Grained Soil Classification Based on Liquid and Plastic Limits From Conventional Tests and Fall Cone Tests

Liquid and plastic limits are used for soil classification of fine-grained soils. Typical determination of liquid and plastic limits is done following ASTM D4318, which is considered as the standard methods for several decades. However, for practical and consistent way of determination of liquid and plastic limits, fall cone tests have been used. This test has potential benefits of improving drawbacks of the ASTM D4318 method, from which the liquid and plastic limits are highly depending on engineer’s skill. The fall cone method produces better accuracy and repeatability in determination of liquid and plastic limits. This study compares liquid and plastic limits from the fall cone test and the tests proposed in ASTM D4318. Then, comparison is made between fine-grained soil classification based on Casagrande’s and Polidori’s plasticity charts using liquid and plastic limits from fall cone test and ASTM D4318 method.