[Home ] [Archive]   [ فارسی ]  
:: Main About Current Issue Archive Search Submit Contact ::
:: Volume 13, Issue 5 (English article specials 2020) ::
jeg 2020, 13(5): 93-120 Back to browse issues page
The Effect of Heating-Cooling Process on Mode I Fracture Toughness of Rocks
Ahmad Jabari1, Mehdi Hosseini 2
1- Department of Mining Engineering, Imam Khomeini International University, Ghazvin
2- Department of Mining Engineering, Imam Khomeini International University, Ghazvin , meh_hosseini18@yahoo.com
Abstract:   (267 Views)

In cases such as explosion, fire, deep drilling and geothermal energy extraction, rocks are exposed to high temperatures influencing the rock toughness. Thus, the aim of this study is to investigate the effect of temperature on the fracture toughness of the rocks. In this study, the effect of temperature on the mode I fracture toughness is investigated. To this end, three-point bending tests were performed on semicircular specimens of four types of natural rocks including sandstone, limestone, tuff, andesite, and a series of concrete specimens to determine the fracture toughness. The specimens were first heated to 100, 200, 300, 500 and 700 °C. After reaching the desired temperatures, the specimens were cooled. A series of tests was performed on the specimens at ambient temperature (25 °C). The heating rate in the electric furnace was 15 °C/min in accordance with the temperature rise in fires. Petrographic studies and X-ray diffraction analysis (XRD) were performed to identify the composition of the rocks. Furthermore, the effective porosity and the weight loss of heated specimens were determined to study the behavior of rocks. Comparison of the test results indicated the higher impact of temperature on the fracture toughness of fine-grained rocks. In addition, the fracture toughness decreased by increasing the effective porosity and decreasing the weight loss. According to the results, the mode I fracture toughness of sandstone, tuff, limestone, andesite and concrete specimens underwent a heating-cooling cycle up to 700 °C respectively decreased 45, 17, 44 and 9.5 and 37 percent compared with that of unheated specimens.
 

Keywords: Fracture toughness, mode I, heating, three-point bending, heating-cooling cycle
Full-Text [PDF 1046 kb]   (56 Downloads)    
Type of Study: Research Paper | Subject: Geotecnic
Received: 2018/10/2 | Accepted: 2019/01/22 | Published: 2020/06/9
Add your comments about this article
Your username or Email:

CAPTCHA


XML   Persian Abstract   Print


Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:

Jabari A, Hosseini M. The Effect of Heating-Cooling Process on Mode I Fracture Toughness of Rocks. jeg. 2020; 13 (5) :93-120
URL: http://jeg.khu.ac.ir/article-1-2824-en.html


Volume 13, Issue 5 (English article specials 2020) Back to browse issues page
نشریه زمین شناسی مهندسی Journal of Engineering Geology
Persian site map - English site map - Created in 0.08 seconds with 32 queries by YEKTAWEB 4207