Experimental investigation on the effects of elevated temperature on geotechnical behaviour of tropical residual soils

Abstract

The engineering performance of soil after exposure to temperature is increasingly important in geotechnical and geoenvironmental engineering. Most thermal remediation of soil concentrates more on the remediation outcome and eliminates the effects temperature will have on the engineering properties of the soil itself. This paper presents the results of laboratory study conducted on two lateritic soils to investigate effect of elevated temperature difference on their geotechnical properties. The soils were classified as A-7-6 (8) and A-7-5 (4) based on the AASHTO soil classification system. After subjecting the soil samples to elevated temperatures (25, 50, 100, 150 and 200 °C), tests such as Atterberg limit, compaction, California bearing ratio (CBR), unconfined compressive strength (UCS) and scanning electron microscopy were carried on the samples. The results showed a decrease in Atterberg limit and increase in maximum dry density. The peak CBR for both the soils was obtained at 150 °C. The UCS increased with curing time but decreased with increased preheat temperature for both soils. The microanalysis result portrayed changes in morphological structure of fabrics which indicates a breakdown in the microstructural properties of the soil due to temperature variation. Generally, the statistical analysis of variance showed that temperature has significant effect on the geotechnical properties of residual soils.

Shear Strength Characteristics of a Thermally Cured Sand-Bentonite Mixture

“…The microscopic studies of Pusch et al [5] to investigate the effects of temperature and confining pressure on bentonite structure showed that application of elevated temperatures for a long time affects montmorillonite flakes to form a denser structure separated by larger voids. The SEM studies performed by Attah and Etim [6] on clayey sand also revealed that the initial porous structure of soil turns to a dense fragmented one after preheating to 150°C for 4 hours. Shirasb et al [7] investigated the effect of thermal pre-curing on consolidation characteristics of a sand-bentonite mixture and showed the transition of behavior from reconstituted to a structured one with a distinct yield stress.…”

Knowledge‐guided machine learning for improving daily soil temperature prediction across the United States

“…There is a growing need to accurately predict soil temperature as a function of depth, location, and time due to its vital role in agriculture (Hatfield & Prueger, 2015; Talaee, 2014), geology (Singh et al., 2017), geothermal applications (Yener et al., 2017; Zajch & Gough, 2021), as well as in geotechnical and geoenvironmental engineering (Attah & Etim, 2020). In agriculture, soil temperature is important for estimating belowground ecosystem processes such as plant germination, root growth and respiration, decomposition, and nutrient transformation and uptake by crop roots (Pathak, 2011; Stottlemyer, et al., 2001; Sun et al., 2018; Waring & Running, 2007; Yi et al., 2008).…”

“…In geology, soil temperature affects the decomposition of soil organic carbon as well as the carbon protection capacity and mechanisms of various clay soils (Hao et al., 2016; Singh et al., 2017). In geothermal and geoenvironmental engineering, prediction of soil temperature is important for determining the engineering performance of soils and for power generation and heat exchanger applications (Attah & Etim, 2020; Chandrasekharam & Bundschuh, 2008; Ozgener et al., 2013).…”

Effect of cyclic heating on some engineering characteristics of some soils from Ilorin, Nigeria

“…The engineering properties of the soils are influenced by the several complex interactions between the compositional and environmental factors [4]. Among the environmental factors, temperature is an important property that can affect the properties of soils and hence the effects of temperature on engineering performance of soils is increasingly receiving attention in geotechnical engineering [4][5][6]. This is because soils may experience induced temperature changes from engineering structures such as groundwater heat pump [7], hot buried or oil and gas pipelines, buried electricity or high-voltage cables [8], and radioactive waste depositories [9].…”

“…Previous works have shown that variations in the induced temperature in soils (either through natural means or engineering structures) can affect the index, hydraulic, compaction, consolidation, and strength properties of soils [6,13,14]. Abu-Zreig et al [15] investigated the effect of increasing temperature on the properties of clayey soils and reported that as the temperature increases (beyond 100 °C), the Atterberg limits, swelling pressure, optimum moisture content and unconfined compressive strength of the soil decrease.…”