Next Article in Journal
A Novel Constraint Handling Approach for the Optimal Reactive Power Dispatch Problem
Previous Article in Journal
The Creep-Damage Model of Salt Rock Based on Fractional Derivative
Previous Article in Special Issue
Assessment of Energetic, Economic and Environmental Performance of Ground-Coupled Heat Pumps
Article Menu
Issue 9 (September) cover image

Export Article

Open AccessFeature PaperArticle
Energies 2018, 11(9), 2350; https://doi.org/10.3390/en11092350

Comparison of Mechanical Behavior and Acoustic Emission Characteristics of Three Thermally-Damaged Rocks

1
State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
2
State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221008, China
*
Author to whom correspondence should be addressed.
Received: 5 August 2018 / Revised: 20 August 2018 / Accepted: 5 September 2018 / Published: 6 September 2018
(This article belongs to the Special Issue Geothermal Energy: Utilization and Technology)
Full-Text   |   PDF [3243 KB, uploaded 6 September 2018]   |  

Abstract

High temperature treatment has a significant influence on the mechanical behavior and the associated microcracking characteristic of rocks. A good understanding of the thermal damage effects on rock behavior is helpful for design and stability evaluation of engineering structures in the geothermal field. This paper studies the mechanical behavior and the acoustic emission (AE) characteristic of three typical rocks (i.e., sedimentary, metamorphic, and igneous), with an emphasis on how the difference in rock type (i.e., porosity and mineralogical composition) affects the rock behavior in response to thermal damage. Compression tests are carried out on rock specimens which are thermally damaged and AE monitoring is conducted during the compression tests. The mechanical properties including P-wave velocity, compressive strength, and Young’s modulus for the three rocks are found to generally show a decreasing trend as the temperature applied to the rock increases. However, these mechanical properties for quartz sandstone first increase to a certain extent and then decrease as the treatment temperature increases, which is mainly attributed to the high porosity of quartz sandstone. The results obtained from stress–strain curve, failure mode, and AE characteristic also show that the failure of quartz-rich rock (i.e., quartz sandstone and granite) is more brittle when compared with that of calcite-rich rock (i.e., marble). However, the ductility is enhanced to some extent as the treatment temperature increases for all the three examined rocks. Due to high brittleness of quartz sandstone and granite, more AE activities can be detected during loading and the recorded AE activities mostly accumulate when the stress approaches the peak strength, which is quite different from the results of marble. View Full-Text
Keywords: thermal damage; compression test; mechanical behavior; acoustic emission; rock type thermal damage; compression test; mechanical behavior; acoustic emission; rock type
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Peng, J.; Yang, S.-Q. Comparison of Mechanical Behavior and Acoustic Emission Characteristics of Three Thermally-Damaged Rocks. Energies 2018, 11, 2350.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Energies EISSN 1996-1073 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top