Effects of water content and salinity on the porosity structure and resistivity of loess soil sintered at 1000 °C

Abstract

The spontaneous combustion of coal in oxygen environment changes the physical and mechanical properties and pore structure of rock and soil. In north of Shaanxi, the Quaternary loess is widely deposited on coal seam. In order to explore the influence of different factors on the change of loess properties after coal fire baking, loess samples with different initial water contents and salt contents were selected for high-temperature sintering. The effects of water content and salinity on the porosity and resistivity of loess after high-temperature baking were analyzed by basic physical property test, resistivity test and nuclear magnetic resonance test. The results show that, under the influence of coal fire, the porosity and main pore size increased with water content or salinity. With the increase of porosity, the resistivity first decreases and then increases. This paper systematically studies the influence of high temperature on the physical properties of loess under different conditions, which provides a reference for studying the effect of coal fire on loess in north of Shaanxi.

Investigating Ultrasonic Pulse Velocity Method for Evaluating High-Temperature Properties of Non-Sintered Hwangto-Mixed Concrete as a Cement Replacement Material

“…However, the existing research on hwangto as a building material primarily focuses on strength development mechanisms and construction at room temperature, and some previously reported studies have discussed the advantages of high-temperature properties of hwangto itself. [ 15 , 16 ]. In previous studies, thermogravimetric (TG) analyses (TG and differential thermal analysis) of hwangto revealed a total of three peaks, with two of these peaks caused by the evaporation of free and absorbed water appearing at temperatures below ~140 °C [ 17 , 18 ].…”