| Studies on the application of rheological properties of clay pastes
from red, black and alluvial clays for the determination of liquid
limit have been further extended to determine the thixotropic coefficient
of various clays at liquid limit consistency. The thixotropic
co-efficient at liquid limit consistency, irrespective of clay mineral
composition varies in a narrow range of 0.7 to 1.50. At this consistency,
the Bingham yield stress and thixotropic area also vary in a narrow
range. The plot between thixotropic co-efficient and moisture content
at liquid limit of various clays holds two linear relationships: (i) for
plastic clays having liquid limit above 50 and (ii) for lean clays having
liquid limit below 50±2. The small variations occurring in thixotropic
co-efficient at liquid limit consistency have been attributed to
the nature of exchangeable and adsorbed ions, organic matter, nonclay
fractions, surface roughness on sand and silt particles etc. |
