Discussion: Measuring the plastic limit of fine soils: an experimental study

Discussion of “Reclaimed Lignin-Stabilized Silty Soil: Undrained Shear Strength, Atterberg Limits, and Microstructure Characteristics” by Tao Zhang, Guojun Cai, and Songyu Liu

“…However, it is important to emphasize that any expected agreement between the wP 100 (or any similarly defined strength based plastic limit values) and the thread-rolling plastic limit values is purely coincidental (Haigh et al 2013;Sivakumar et al 2016;O'Kelly et al 2018). The thread-rolling plastic limit corresponds to the remolded state, as emphasized earlier, whereas the values deduced in the authors' investigation are for 7 d cured soil specimens.…”

Editorial

“…In reply, the authors explain that the PL (100) value is the plastic strength limit and is fundamentally different from the conventional plastic limit. In the second discussion, Haigh and Vardanega (Sivakumar et al, 2016b) state that the original paper is an excellent contribution representing a major advance to get PL (100) into mainstream use and is a welcome addition to the literature at this time with the development of new European soil testing standards. The third discussion is on the paper with empirical correlations for the compression index of Irish soft soils by McCabe et al (2014).…”