New Relationship between Linear Shrinkage and Shrinkage Limit for Expansive Soils

Abstract

In Indonesia’s engineering practice, a standard laboratory test method to describe the characteristics of expansive soils is the shrinkage limit (ASTM). Expansive soils are problematic soils that have shrinkage and swelling history due to changing water content on a particular clay mineral type (i.e., montmorillonite). Another method rare using in general practice in our country is the linear shrinkage (British Standard). The last test is easier and faster to obtain than the shrinkage limit method. Some researchers proposed swelling potential classification for expansive soils using a specific range of shrinkage limits or linear shrinkage. This research aims to give a new relationship between both methods using available laboratory test results database. There were two sets of data: first, complete laboratory data (i.e., 124 samples of shrinkage limit and linear shrinkage); and second, only Atterberg limits (i.e., liquid limit and plastic limit) results (i.e., 86 samples). For the latter database, shrinkage limit and linear shrinkage use previous researchers’ empirical equations. Then, these two datasets are compared and give a similar trend. The results show that if increasing of shrinkage limit is followed by decreasing of linear shrinkage. This result may help geotechnical engineers to obtain the linear shrinkage directly from our proposed Equation and shrinkage limit value. Hence, our research has a contribution to know the characteristics of the expansive soil (i.e., swelling potential).