Clay Characterization of Tiller Flotten Quick Clay

Rene Tammen , Kamila Zabłocka, Klaartje de Weerdt, Erika Eiser

In this study, we investigate the mineralogical and physicochemical properties of the Tiller–Flotten quick clay formation in Trondheim, Norway.
The objective is to enhance our understanding of particle interactions within this quick clay system, thereby contributing to the development of more environmentally friendly stabilization strategies. A comprehensive suite of analytical techniques was employed, including X-ray diffraction (XRD), X-ray fluorescence (XRF), and energy-dispersive spectroscopy coupled with scanning electron microscopy (EDS-SEM). Compared to other quick clay formations, biotite was found to be the most abundant clay mineral, followed by illite and chlorite. The specific surface area (SSA) was determined to be ~28 m² g⁻¹, and the cation exchange capacity (CEC) was less than 4 meq 100 g⁻¹. These findings may help explain the distinct behavior of the Tiller–Flotten quick clay compared to other formations. Zeta-potential measurements were conducted using different salts at concentrations of 25, 50, and 100 mmol/L. Among those, MgCl₂ and CaCl₂ induced the most significant changes in the zeta potential. The other salts (NaCl, KCl, K₂SO₄, K₂CO₃, and KOH) resulted in more negative zeta potentials of −50 mV compared to the initial value of −32 mV in distilled water. Increasing the concentration of those salts led to a reduction in the diffuse double layer. However, even at 100 mmol/L, the zeta potential changed only slightly. Additionally, K₂CO₃ and KOH significantly increased the pH to 10–12, further influencing the electrochemical behavior of the clay particles.