Laboratory Investigation of the Effects of Temperature on the Mechanical Properties of Sandstone

Abstract

An experimental study has been carried out as part of a wider programme of research in order to examine some of the physico-mechanical properties of the Jiaozuo Sandstone after exposure to extremely high temperatures. The mechanical properties of the rock under examination are discussed before the results of the thermo-mechanical response of the sandstone are presented and analysed. The range of temperature to which the sandstone has been exposed is 20-1,200°C. The physical properties considered include the shape, volume, mass and density changes and the velocity of longitudinal and transverse elastic waves through the samples, before and after exposure to high temperature. The mechanical properties considered include the stress-strain response, the uniaxial compressive strength, the modulus of elasticity and the Poisson's ratio. The results are analysed and discussed and possible mechanisms for the observed thermomechanical response, are postulated.

Effect of high temperatures on sandstone – a computed tomography scan study

“…Both sandstones experienced a significant reduction of YoungÕs modulus when the preheating treatments increased from 400 to 800 ¡C, with an average reduction of about 50 % and 40 % for fine and coarse sandstone, respectively. Similar variation patterns of the YoungÕs modulus of sandstone under increasing temperature were reported by Wu et al (2013). …”

“…Temperature dependent mechanical parameters such as strength, elastic modulus and Poisson's ratio are the basic parameters relevant to deep underground excavation support design and stability analyses. Hence, the impact of high temperatures on rocks is considered as an important topic in rock mechanics.The deformation mechanisms and failure criteria of different types of rocks at high temperatures has been studied by various researchers (Stesky et al 1974;Heuze 1983;Rao et al 2007;Wan et al 2009;Zhang et al 2009;Chen et al 2012;Ranjith et al 2012;Brot-ns et al 2013;Wu et al 2013;Liu et al 2013;Zhang et al 2014) and it has generally been shown that high temperature has a significant effect on the mechanical properties of rocks. However, the extent of the effect has been shown to vary for different types of rock, depending on factors such as mineral composition, porosity, density, and presence of cracks.…”

“…At high temperatures, varying thermal expansion characteristics within different mineral grains causes thermal stresses in the mineral structure to increase, potentially leading to the fracture of individual mineral grains and expansion of inner cracks, which may further lead to disaggregation of the rock (Huotari and Kukkonen 2004;Wan et al 2009;Zhang et al 2014). In addition to structural deformation induced by mineral expansion, other factors which may lead to alteration of the rock internal structure include dehydration, decomposition, melting, and phase-change reactions (Zhang et al 2005;Tian et al 2012;Wu et al 2013).The data presented indicates that high temperatures have a significant effect on the mechanical properties of sandstone. The changes due to heating can be divided into three stages.…”

Investigations of Thermal Damage on the Physical and Mechanical Properties of Gneiss Rock Specimen

“…Many experimental studies have been conducted on different rocks, [1][2][3][4][5][6][7][8][9][10][11][12][13][14] with an objective to observe and explain the behavior of physical and mechanical properties of these rocks under high temperature or after thermal treatment. All these experimental works are focus on sandstone [4][5][6][7], granite [1,[8][9][10], carbonates [2] and gabbro [11].…”

“…All these experimental works are focus on sandstone [4][5][6][7], granite [1,[8][9][10], carbonates [2] and gabbro [11]. However, few studies are interested on the gneiss rock microscopic analysis of thin section of the heated specimen.…”