Dielectric Permittivity of Loess from the Central Area of Argentina

RINALDI, VICTOR A; FRANCISCA, FRANCO MATÍAS

Foz do Iguassu

Conferencia; XI Panamerican Conference on Soil Mechanics and Geotechnical Engineering; 1999

The complex relative dielectric permittivity or dielectric constant is the fundamental parameter that control propagation of electromagnetic waves in materials. This work presents a fundamental study on the complex dielectric constant of the collapsible loess from the central area of Argentina. Samples of loess were recovered and tested with different degree of saturation in the frequency range of 20 MHz to 1.3 GHz. An approach is presented to establish a relationship between the real dielectric constant and mineral composition of loess. At high and medium moisture content, loess behaves as a conducting material due to the large concentration of soluble salts. This effect enhances real and imaginary relatives permittivities in the lower frequency range of this work. At frequencies close to 1 GHz, the real dielectric constant depends mainly from the amount of free and bound water present in the soil. In this case, it is showed that theoretical and empirical mixture models predict acceptably the observed behavior