Open AccessRheological behaviour of clays in plastic state
Author(s) -
Jhon Fredy Rincón-Morantes,
Javier Camacho Tauta,
Óscar Javier Reyes-Ortiz
Publication year - 2021
Publication title -
engineering review
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.198
H-Index - 11
eISSN - 1849-0433
pISSN - 1330-9587
DOI - 10.30765/er.1503
Subject(s) - rheology , plasticity , materials science , atterberg limits , shear modulus , viscoelasticity , soil water , dynamic modulus , moduli , rheometer , shear (geology) , dynamic mechanical analysis , geotechnical engineering , sweep frequency response analysis , composite material , water content , geology , soil science , physics , quantum mechanics , polymer
Clayey soils exhibit viscoelastic behaviour in the plastic state, implying simultaneous retentive and dissipative mechanical properties as well as strain rate dependent properties. Such response is partially captured by the socalled Atterberg plastic limits. A more comprehensive evaluation of the mechanical response of this type of soils in the plastic state can be obtained by testing in a dynamic shear rheometer. Clayey soils consisting of different proportions of kaolin and bentonite and different water contents were subjected to dynamic shear tests to measure their rheological properties. All tests were performed with a constant strain amplitude of 10%, a fixed range frequency sweep (0.1 Hz to 100 Hz) and a constant temperature of 20°C. The results show that the complex shear modulus has an inverse relationship with the soil water content and a direct relationship with the plasticity index. Moreover, the phase angle increases slightly and then decreases suddenly as the frequency increases. The complex shear moduli obtained by dynamic tests were compared with the oedometric moduli estimated by correlations and showed satisfactory trends between them. The study contributed to the understanding of the complex behaviour of soils in the plastic state. Although the mechanical response of these materials is affected by some factors, the plasticity limits were consistent with the complex moduli under analogous conditions of strain and frequency.