Determination of Atterberg limits using newly devised mud press machine

• Plastic limit test is thought to have no rational basis.
• Although LL and PL are akin to each other, they are determined by different tools.
• Liquid limit and plastic limit tests involve a number of certainties.
• The new method is free of operator effects It determines the liquid and plastic limits with a great degree of success.

Consistency limits are one of the most prominent parameters to be determined in geotechnical investigations. While these limits are akin to one another, different tools determine each one. Each method of determining consistency limits has its own uncertainties, the operator dependency being the top source of uncertainty. Liquid limit (LL) and plastic limit (PL) tests have a number of uncertainties affecting the test results. The very speculative nature of the bead-rolling method for the plastic limit has long been known. Besides this, its results can be barely accepted as quantitative. In the past, a number of attempts have been made to eliminate these setbacks for Atterberg limits. The scope of this investigation is to evaluate the potential of newly developed “mud press method (MPM)” to predict the two consistency limits. The material employed for this investigation covers 275 soils, whose liquid limits range from 28 to 166. The log(a) and 1/b parameters obtained from the MPM method were correlated to results of the conventional methods. The PL and LL for each soil were predicted using empirical forms and were compared with the laboratory values. Remarkably good matches were obtained between the conventionally determined test results and the predicted values for the liquid and plastic limits. The newly developed tool is superior in several aspects to the available conventional methods and tools.