Electrical Resistivity Characteristics and Mechanism of Solidified Loess Mixed with Calcium Oxide-modified Red Mud

Abstract

Purposes This study focues on the resistivity characteristics and mechanism of solidified loess mixed with CaO-modified red mud. Methods The resistivity of the samples with different CaO and red mud contents and curing ages was tested. In addition, XRD, SEM, EDS, porosity, and porethroat distribution of these samples under different conditions were tested to analyze the mechanism of resistivity change. Findings The results show that the resistivity decreases with the increase of CaO and red mud contents. Compared With respect to cement solidified soil, the types and concentrations of conductive ions increase in pore water of the cement solidified soil modified by CaO and red mud, which leads to the increase of conductivity of pore water. With the increase of curing age, the resistivity overall presents a trend of logarithmic increase. because of the excessive CaO unreacted in the solidified soil, the conductive ions still exist in pore water. Therefore, the decrease of pore water conductivity is limited when the curing age is longer than 28 days. Moreover, owing to the increase of the porosity and pore-throat distribution of the cement solidified soil modified by CaO and red mud, the internal disconnecting paths increase and the conduction paths reduce, which increases the resistivity with the increase of curing age.

Keywords

• solidified soil
• resistivity
• porosity
• sem
• xrd