CSIR Central

Effects of Elevated Temperatures on the Microstructural, Physico-Mechanical and Elastic Properties of Barakar Sandstone: A Study from One of the World’s Largest Underground Coalmine Fire Region, Jharia, India

IR@CIMFR: CSIR-Central Institute of Mining and Fuel Research, Dhanbad

View Archive Info
 
 
Field Value
 
Title Effects of Elevated Temperatures on the Microstructural, Physico-Mechanical and Elastic Properties of Barakar Sandstone: A Study from One of the World’s Largest Underground Coalmine Fire Region, Jharia, India
 
Creator Singh, Ashok Kumar
 
Subject Rock Testing
 
Description Experimental investigations of the effects of elevated temperature on microstructural, mineralogical, physico-mechanical and elastic properties of rocks were carried out to understand the effect of underground coal fire along with thermal damage and failure initiation in Barakar sandstone from the Jharia coalfield, India. Discolouration analysis, petrographic studies, scanning electron microscopy, thermogravimetry, differential thermal analysis and electron probe micro analysis were carried out to understand the microstructural and mineralogical changes in thermally treated samples. The experimental results suggest that the changes in investigated properties follow three characteristic thermal zones: zone I (25–300 °C), zone II (300–500 °C) and zone III (500–800 °C). Among all, zone II is a prominent transition region where a rapid increase in crack density, porosity and thermal damage is observed along with a sharp reduction in seismic wave velocities, uniaxial compressive strength, tensile strength and elastic parameters. Development of thermal stress-induced intergranular and intragranular micro-cracks, evaporation of organic matters, and dehydration and thermal decomposition of minerals are the most conspicuous reasons for the observed changes in this zone. Zone III is characterized by phase transformation of quartz, recrystallization and partial melting of cement and phyllosilicates that filled some of the existing micro-cracks, resulting in a local change of porosity, strength and elastic properties. Developments of different failure modes are observed in different temperature ranges such as simple shear along a single plane in zone I, progressive growth of Y-shaped (double plane) shearing in the zones II and III (400–700 °C) and axial splitting at 800 °C. The results from this study provide comprehensive elaboration of thermal effects on sandstones at a particular temperature range.
 
Publisher Springer
 
Date 2021-01
 
Type Article
PeerReviewed
 
Identifier Singh, Ashok Kumar (2021) Effects of Elevated Temperatures on the Microstructural, Physico-Mechanical and Elastic Properties of Barakar Sandstone: A Study from One of the World’s Largest Underground Coalmine Fire Region, Jharia, India. Rock Mechanics and Rock Engineering , 54. pp. 1293-1314. ISSN 0723-2632
 
Relation http://cimfr.csircentral.net/2456/