The influence of selected chemical compounds used in winter road maintenance on the active capillarity of soils

Abstract

Purpose Winter road maintenance involves the use of various chemical compounds which affect the active capillarity of soils. The main goal of the study was to determine a model to predict changes in the active capillarity of soils using distilled water and water solutions of chemical compounds which are used in winter road maintenance. The purpose of the first part of the experiment was to determine a model to predict changes in the height of capillarity rise and the rate of capillary rise with time. The second part of the experiment investigated how water solutions of selected chemical compounds altered the soils' active capillarity as determined using distilled water. Materials and methods The research was carried out on three soils from deposits in west-central Poland, and their separated fractions. Active capillarity was investigated with the use of distilled water and 5 and 10 % solutions of ten chemical compounds used in winter road maintenance. The rate and height of capillary rise were measured in transparent vertical tubes, placed vertically in a glass tank into which the distilled water or solutions of chemical compounds were poured. Results and discussion The rate of capillary rise was decreasing as a function of time. After the first part of the experiment had been completed, an analysis was made of the statistical fit between the experimental data for capillary rise of distilled water in the studied soils and soil fractions, and the model described by the formula hðtÞ ¼ h 1 þ v 1 Â lnðtÞ, where h 1 denoted the height of capillary rise in the first second, v 1 denoted the rate of capillary rise, and t denoted time. High determination coefficients indicated a good fit of the model to the experimental data. In the second part of the study, it was found that solutions of chemical compounds caused a reduction in the active capillarity of the studied soils relative to the capillarity determined using distilled water. It was possible to determine a capillarity coefficient w k so as to compare the capillary rises in soil of distilled water and of the various chemical compounds in 5 and 10 % solution. Analysis of the results showed that the capillarity coefficient w k is a characteristic feature which depends on the type and concentration of the chemical subject to capillary action and on the type and fraction of soil.Conclusions The active capillarity of soil depends on the type and concentration of the capillary fluid such as distilled water or water solutions of chemical compounds used in winter road maintenance and other factors. The relation between the height of capillary rise h and time t can be described using the formula hðtÞ ¼ h 1 þ v 1 Â lnðtÞ. The water solutions of chemical compounds used in winter road maintenance caused a reduction in the active capillarity of the studied soils relative to the capillarity determined using distilled water. It was found that the susceptibility of soil to capillary rise can be determined based on the capillarity coefficient w k . This coefficient depends on the ty...

The effect of de-icing roads with salt on the environment in Krakow (Poland)

“…The salinity of soil changes its properties. NaCl reduces water circulation in the soil and changes the air ratios, thus reducing the ground permeability and aeration, affects structure of soil aggregates, humidity, buffering capacity or pH (Ramarkishana & Viraraghavatan 2005, Ćwiąkała et al 2012, Provin & Pitt 2019. During evaporation, salts remain in the soil, whereas excessive salinity causes sodium to displace other cations, including hydrogen ions, which contributes to soil alkalization.…”