Evaluating the Influence of Montmorillonite Content on Swelling Behaviour in Relation to Its Plasticity

Mineralogy is the major parameter to be considered while dealing with expansive soils. Montmorillonite among different minerals in clay soils is the prime reason behind volume change behaviour. These contents may vary with the origin of the soils, and so does the swelling behaviour. Their estimation with respect to different soils offers better accuracy in swell determination. The current study aimed to investigate the influence of Montmorillonite Content (MMC) on swelling behaviour in relation to its plasticity. To do the same, soil samples have been collected from different locations across India, i.e. Bhopal, Guntur, Kendrapara, Warangal, Vijayawada, Kakinada, Mysore, Raipur and Nagpur, and subjected to experimental investigation. The consistency limits, swelling, and MMC of the respective soil samples were determined by employing Atterberg’s limits, free swell index (FSI), and XRD analysis, respectively. From the measured values, relationships were established between MMC and FSI in reference to their plasticity (i.e. CH and CL). It was observed that the swelling increases linearly with MMC in both CH and CL cases, irrespective of the location. However, more scatter can be observed in the case of CL when compared to CH, which is likely due to the variation of MMC and their associated minerals. It is essential to know the mineralogy of soils for better estimation of swelling behaviour to avoid infrastructural failures, especially in arid regions.