Variations of Physical and Mechanical Properties of Heated Granite After Rapid Cooling with Liquid Nitrogen

Wu, Xiaoguang; Huang, Zhongwei; Song, Hengyu; Zhang, Shikun; Cheng, Zhen‐Qiang; Li, Ran; Wen, Haitao; Huang, Pengpeng; Dai, Xianwei

doi:10.1007/s00603-018-1727-3

Cited by 139 publications

(37 citation statements)

References 41 publications

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“…This part of the curve represents the duration of the fire. (c) Finally, the cooling process is simulated in different ways [60,61]: on one hand, some authors cool down the samples within the oven up to room temperature to simulate the slow and natural cooling of the rock. On the other hand, the cooling can be performed in a faster way, by introducing the samples into water or even applying liquid-nitrogen to cause a thermal shock that reproduces the action of extinguishing fires with waters.…”

Section: Source Area: Effects Of Fires On the Rock Massmentioning

confidence: 99%

Effects of Wildfire on Rockfall Occurrence: A Review through Actual Cases in Spain

et al. 2021

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Understanding processes and conditions that lead to rockfalls during and after a wildfire in different geological contexts is crucial since this phenomenon is one of the major hazards in mountainous regions across Europe. Spain is one of the European countries with the highest rate of wildfires, and rockfalls cause high economic and social impact, with many fatalities every year. The increase of rockfalls during and after wildfires is connected with the merging of different factors, not only in the detached area but also in the propagation and potentially affected area. When wildfire occurred, many actions take place: changes in the mechanical conditions of the rocks, the loss of protective capacity from vegetation, the effect induced by firefighting activities and/or the impact by the high temperatures in the adopted protective measures. After the wildfire, there is an increase in frequency and intensity of rockfalls in the burned area, causing a major impact of rockfalls on not only road networks and built-up areas but also people living. Additionally, the removal of vegetation by wildfires causes an increase in the risk perception, related not only to detached blocks but also to the general appearance of the rock mass. In this review, the main factors that influence the occurrence of rockfalls after a wildfire are analyzed, and three actual case studies in Spain are presented to support the variety of conclusions obtained.

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Section: Source Area: Effects Of Fires On the Rock Massmentioning

confidence: 99%

Effects of Wildfire on Rockfall Occurrence: A Review through Actual Cases in Spain

et al. 2021

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“…In 2019, Wu et al [24] presented their results on Shandong granite samples heated between 25°C and 600°C to evaluate the behavior of their physical and mechanical Advances in Civil Engineering properties. e heating rate used here was 5°C/min and L/ D � 2.04. e authors demonstrated that using nitrogen for the sudden cooling of a heated material induced its significant damage, unlike using water or air.…”

Section: Introductionmentioning

confidence: 99%

“…Normalized Young's modulus of certain rocks as function of temperature. and Miskovsky, 2012)[9] Granite (Saiang and Miskovsky, 2012)[9] Schist (Saiang and Miskovsky, 2012)[9] Sandstone (Yu et al, 2015)[13] Granite(Wu et al, 2019) [24] Granite (Isaka et al, 2018)[54] Static Poisson's ratio of sandstone as a function of temperature.…”

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confidence: 99%

Experimental and Theoretical Investigations of Hard Rocks at High Temperature: Applications in Civil Engineering

Leroy

Marius

Nicolas

2021

Advances in Civil Engineering

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This review paper aims to survey and discuss recent theoretical and experimental works reporting the temperature effects on the mechanical properties of rocks like granite, gabbro, gneiss, marble, sandstone, basalt, limestone, and argillite to permit the new challenge in this domain. The effect of high temperatures on various mechanical and physical material properties (Young’s modulus, porosity, tensile and compressive strengths, P-wave velocity, permeability, thermal damage, and expansion) is analyzed. This work shows that hard rock mechanical and physical properties evolutions are strongly related to the evolution of the microstructure caused by the geological history, cracks nucleation occurrences, recrystallization, dehydroxylation, and dehydration reactions. However, it should be emphasized that these studies were not conducted on all types of intrusions and all rocks types. Meanwhile, it has been noticed that variations in temperature could lead to contradictory phenomena. Therefore, different trends were observed for the evolution of physical properties of rocks. There is an increase in porosity approximately 80% above 500°C. In general, for volcanic’s rock, the loss mass and thermal conductivity were drastically observed at low temperatures around 200°C with an antinomic phenomenon. Sandstone, granite, and argillite present the model whose behaviors with thermal load are too much explored accordingly with experiments compared with other rocks. Argillite at 200°C and sandstone and granite at 400°C undergo seriously damage. There is 100°C gap between the results obtained in real-time and those obtained after cooling. Moreover, 300°C can be considered as the critical temperature for real-time temperature heat treatment at which rocks lose almost about 80% of their performance. Otherwise, it is not easy to predict the behavior at high temperature of volcanic rocks like basalt and metamorphic rocks like gneiss which present the complexity in their behavior. For plutonic and metamorphic rocks, 600°C is the critical thermal load. At this temperature, the modulus of elasticity as well as the compressive strength of the most explored rock shows a significant decrease of about 75% for hard rocks. In sum, high temperature damages significantly the mechanical performance of rock. It is the reason for which these results may be useful to characterize the damage and thus predict the dramatic consequences of large temperature fluctuations on engineering structures in the rock.

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“…From the above, there are few studies on permeability enhancement and thermal damage in coal and rock induced by heating-cooling treatment. Wu et al [51,52] used shale and granite specimens to study the variation of physico-mechanical properties under heating-cooling treatment. Their results demonstrated that the permeability of heated specimens significantly increased after LN 2 -cooling treatments, while the density, P-wave velocity, strength and elastic modulus decreased.…”

Section: Introductionmentioning

confidence: 99%

Microcrack evolution and permeability enhancement due to thermal shocks in coal

Zhang

Wang

et al. 2020

PLoS ONE

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To understand the effects of thermal shock on microcrack propagation and permeability in coal, thermal shock tests were conducted on coal specimens by using a constant temperature drying oven (105˚C) and a SLX program controlled cryogenic tank. The growth and propagation of microcracks were measured with computer tomography (CT) scanning and scanning electron microscope (SEM) tests. Results showed that thermal shocks improved the permeability of coal significantly. Notably, the permeability of coal after thermal shocks increased from 211.31% to 368.99% and was positively correlated with temperature difference. CT scanning images revealed that thermal shocks increased the crack number, crack volume and crack width as well as smoothened and widened the gas flow paths, thereby enhancing coal permeability. Moreover, SEM images showed that heating-cooling shocks created more new microcracks, forming more complex crack propagation paths and better connectivity among microcracks in coal compared to cooling shocks. We proposed a crack propagation criterion for coal to explain the mechanism of crack failure and propagation during thermal shocks. Our experiment results and theoretical analysis indicate that the heating-cooling shock is more effective in damaging and breaking coal than the cooling shock. Thus, it can be used as an alternative approach to enhance coal permeability in the production of coalbed methane (CBM).

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Variations of Physical and Mechanical Properties of Heated Granite After Rapid Cooling with Liquid Nitrogen

Cited by 139 publications

References 41 publications

Effects of Wildfire on Rockfall Occurrence: A Review through Actual Cases in Spain

Effects of Wildfire on Rockfall Occurrence: A Review through Actual Cases in Spain

Experimental and Theoretical Investigations of Hard Rocks at High Temperature: Applications in Civil Engineering

Microcrack evolution and permeability enhancement due to thermal shocks in coal

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