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Article
Effect of Heat Treatment on Dynamic Properties of Selected Rock Types Taken from the Salt Range in Pakistan
Arabian Journal of Geosciences
  • M. Farooq Ahmed
  • Umer Waqas
  • Muhammad Arshad
  • J. David Rogers, Missouri University of Science and Technology
Abstract

Temperature is one of the variables that influence the elasto-plastic behavior and integrity of rock outcrops. Fluctuations in temperature can trigger alteration of some of the mineral properties and impact the brittle-plastic transition. Initiation and propagation of thermally induced tension cracks tend to weaken most rock types. The principal goal of this study was to anticipate impacts of thermal stress-strain cycles on the dynamic response of representative rock units exposed in the Khewra Gorge of the Salt Range Punjab of Pakistan. Ten types of sedimentary rock units were sampled, including marl, dolomite, three types of limestone, and five different sandstones exhibiting varying characteristics in outcrop. Boulder specimens were collected from the field and transported to the laboratory to prepare 50 drill cores that could be subjected to thermal cycling between 50 and 200°C in increments of 50°C. Room temperature core samples were tested using an Erudite resonance frequency meter to measure their Q-factors and the resonance frequency (Fr) at an applied loading frequency of 7 KHz with 0.01 V output voltage. Results suggest that thermal cycling tends to reduce the dynamic Young's modulus (Ed) and Q-factor. Other parameters, such as damping ratio (ξ), specific damping capacity (Ψ), and loss factor ( ) appeared to increase with increasing temperature cycles, likely as a result of developing thermally induced tensile fractures. The resultant values of the null hypothesis (t-critical and t-stats) suggests that the null hypothesis can be discarded because there was no observable difference between the measured and expected values for the cores tested. The observations and data emanating from this study might be useful in designing low-level radioactive waste landfills, nuclear waste repositories, and deep underground excavations where the increased temperature could alter the mechanical behavior of the parent rock mass.

Department(s)
Geosciences and Geological and Petroleum Engineering
Keywords and Phrases
  • Damping ratio,
  • Dynamic Young's Modulus,
  • Resonance frequency,
  • Strength reduction,
  • Thermal cracks,
  • Thermal cycling
Document Type
Article - Journal
Document Version
Citation
File Type
text
Language(s)
English
Rights
© 2018 Saudi Society for Geosciences, All rights reserved.
Publication Date
11-1-2018
Publication Date
01 Nov 2018
Citation Information
M. Farooq Ahmed, Umer Waqas, Muhammad Arshad and J. David Rogers. "Effect of Heat Treatment on Dynamic Properties of Selected Rock Types Taken from the Salt Range in Pakistan" Arabian Journal of Geosciences Vol. 11 Iss. 22 (2018) ISSN: 1866-7511; 1866-7538
Available at: http://works.bepress.com/j-rogers/91/