29 International Journal of Science and Engineering Investigations vol. 9, issue 107, December 2020 ISSN: 2251-8843 Received on December 21, 2020 Thermal Image Analysis of a Cement Kiln Dust Treated Slope Hamid Ranjkesh Adarmanabadi 1 , Arezou Rasti 2 , Mehrdad Razavi 3 1,2,3 Department of Mineral Engineering, New Mexico Institute of Mining and Technology, Socorro, NM, USA ( 1 hamid.ranjkesh@student.nmt.edu, 2 arezou.rasti@student.nmt.edu, 3 mehrdad.razavi@nmt.edu) Abstract- This study presents the effects of additives such as cement kiln dust (CKD) to stabilize the soil on soil thermal images due to the changes in the treated soil's thermal properties. In Socorro, NM, a natural soil slope treated with different amounts of CKD to reduce erosion in 2008 was selected for this research. The slope was divided into four sections; the 30 cm of the slope surface in these sections was treated with 0%, 5%, 10%, and 15% of CKD (by soil's dry weight). In 2019, a soil pH distribution map of the slope showed traces of CKD concentration in each section and proportional to the CKD concentration in 2008. The slope's thermal images were captured for twelve hours, starting at 6:30 am on an hourly basis. A small-scale test model of the slope was also built in the lab using the untreated native slope soil to increase thermal images' resolution. The test-model was exposed to the outside environment, and the thermal images were captured using the same time capture-schedule of the field slope. The thermal image analysis results of both the field test and the small-scale test revealed the visible changes in the thermal images of different sections treated with different amounts of CKD due to the reduction of thermal diffusivity and improved treated soil's thermal conductivity. This study shows that thermal image analysis is an effective method to detect the treated soils with additives affecting soil thermal properties, such as CKD and the additive concentration in soil, in conjunction with traditional techniques. Keywords- Thermal Behavior, Cement Kiln Dust (CKD), Thermal Conductivity, Thermal Imaging Analysis I. INTRODUCTION Soil temperature is an influential parameter affecting plant processes and soil microbial diversity (Sabri et al., 2018). The study of soil thermal behavior is essential since soil thermal properties significantly affect engineering applications (Kang et al., 2015). Several investigations are surveying heat-related problems in geotechnical engineering. It is a significant concern that should be taken into account; for example, it is crucial to know the heat capacity and thermal conductivity of soil to estimate heat transfer in soil. The thermal behavior of soil close to the surface is a fundamental parameter to examine the air-soil interface's energy balance at the ground's surface (Hopmans & Dane, 1986; Kodikara et al., 2011). The heat flow at any depth in the soil is proportional to the temperature gradient at that point, and the proportionality coefficient is the thermal conductivity. Thermal diffusivity is the ratio of thermal conductivity to volumetric heat capacity (Shiozawa & Campbell, 1990). There are different techniques in order to survey the thermal conductivity of the soil. The single probe method can be used to estimate the thermal conductivity of the soil. Abu-Hamdeh and Reeder (2000) followed a laboratory experiment to survey the thermal conductivity of sand, sandy loam, loam, and clay loam using the single probe method. Ochsner et al. (2001) investigated the soil thermal properties by using the heat-pulse method. Heat capacity, thermal diffusivity, and thermal conductivity are parameters that were surveyed in their study. They concluded that the volume fraction of water, volume fracture of solids, and volume fraction of air in the soil are crucial parameters affecting the soil thermal properties. The Decagon Devices KD2 Pro Thermal Properties Analyzer is another method employed by Kang et al. (2015) to record all the soil's thermal conductivities. Kodikara et al. (2011) highlighted the application of thermal imaging for geotechnical engineering investigations. Additionally, they suggested that thermal imaging can be effectively used to estimate the soil's thermal diffusivity in the laboratory. Thermal diffusivity of soil can be measured directly and indirectly by using several different techniques. Besides, various methods were suggested to estimate soil's thermal properties by recording the field's temperature. Thermal imaging is a method of converting an object's visible radiation pattern (e.g., soil) into visible images. Thermal imaging is a non-contact and non-destructive technique that has many applications due to its ease of use. It can produce an overall picture of the temperature distribution on the subjects and provide an accurate temperature of the surface viewed (Kodikara et al., 2011). The thermal camera converts the invisible infrared radiation released by subjects into temperature and displays as thermal images (Rao, 2008). Chemical additives such as cement, cement kiln dust (CKD), and lime can improve soil formations' engineering properties (Faramarzi et al., 2016). Various investigators have reported the effect of additives material on soil's thermal behavior; for example, Folaranmi (2009) determined the effect of different amounts of fly ash and sawdust on clay's thermal conductivity. The study results showed that additive material such as ashes, sawdust, animal dung, and bentonite improve clay's thermal conductivity. Edet et al. (2017) investigated the effect of additives on Loamy soil's thermal conductivity in Calabar, Nigeria. The result of their study reveals that the thermal conductivity of Loamy soil increases with additives.