Mechanical properties of Beishan granite under complex dynamic loads after thermal treatment

Li, Yubai; Zhai, Yue; Wang, Chengshan; Meng, Fandong; Ming, Lü

doi:10.1016/j.enggeo.2020.105481

Cited by 39 publications

(23 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is preferred for general construction use as raw material in civil engineering practice and for building high-volume structures with special requirements. The increasing use of this rock type is the host rock of a subsurface radioactive waste disposal facility, implemented or planned in many countries [4,5].…”

Section: Introductionmentioning

confidence: 99%

Heat-related Changes of Density, P-wave Velocity, and Surface Hardness of Granite

Németh

Török

2021

Period. Polytech. Civil Eng.

View full text Add to dashboard Cite

Low- and intermediate-level radioactive waste is stored in the National Radioactive Waste Repository in Bátaapáti in Hungary. The repository is located in the Carboniferous Mórágy Granite Formation. This paper focuses on heat-related changes of physical properties such as bulk density, P-wave velocity, P-wave modulus, and Duroskop surface hardness of the dominant lithology: monzogranite. Cylindrical specimens were tested at laboratory conditions (22 °C) and were heat-treated up to 250 °C, 500 °C, and 750 °C. The properties were measured before and after the thermal strain. After heat-treatment, the monzogranite samples became brownish, and at 750 °C, cracks appear at the surface of the specimens. Laboratory test results show that bulk density values slightly decrease from room temperature to 250 °C treatment and further dropped at 500 °C and especially at 750 °C. P-wave velocity values and the connected P-wave modulus tend to decrease from room temperature to 750 °C significantly. Duroskop rebound values show slight declines in the surface strength of the specimens until 500 °C, and then a drastic decline at 750 °C. Heat treatment tends to alter the physical properties of the monzogranite. From room temperature to 500 °C, a slight but apparent decrease between 500 °C and 750 °C significant reductions in the bulk density, P-wave velocity, and Duroskop values. Behind the physical alterations are the different thermal-induced expansion of minerals and mineral alteration at elevated temperatures.

show abstract

Section: Introductionmentioning

confidence: 99%

Heat-related Changes of Density, P-wave Velocity, and Surface Hardness of Granite

Németh

Török

2021

Period. Polytech. Civil Eng.

View full text Add to dashboard Cite

show abstract

“…The velocity of the striker bar can be changed by charging different levels of pressures in the gas gun, which further vary the strain rate on the specimen [45]. The impact pressure in each group of experiments was set to 0.055 MPa, and then the variation of dynamic mechanical behavior of sandstone specimens with freezing temperature was studied.…”

Section: Shpb Testsmentioning

confidence: 99%

Degradation of Mechanical Behavior of Sandstone under Freeze-Thaw Conditions with Different Low Temperatures

Gao

et al. 2021

Applied Sciences

View full text Add to dashboard Cite

This study investigated the effects of freezing temperature under freeze-thaw cycling conditions on the mechanical behavior of sandstone. First, the sandstone specimens were subjected to 10-time freeze-thaw cycling treatments at different freezing temperatures (−20, −40, −50, and −60 °C). Subsequently, a series of density, ultrasonic wave, and static and dynamic mechanical behavior tests were carried out. Finally, the effects of freezing temperature on the density, P-wave velocity, stress–strain curves, static and dynamic uniaxial compressive strength, static elastic modulus, and dynamic energy absorption of sandstone were discussed. The results show that the density slightly decreases as temperature decreases, approximately by 1.0% at −60 °C compared with that at 20 °C. The P-wave velocity, static and dynamic uniaxial compressive strength, static elastic modulus, and dynamic energy absorption obviously decrease. As freezing temperature decreases from 20 to −60 °C, the static uniaxial compressive strength, static elastic modulus, dynamic strength, and dynamic energy absorption of sandstone decrease by 16.8%, 21.2%, 30.8%, and 30.7%, respectively. The dynamic mechanical behavior is more sensitive to the freezing temperature during freeze-thawing cycling compared with the static mechanical behavior. In addition, a higher strain rate can induce a higher dynamic strength and energy absorption.

show abstract

“…Among the many investigated mechanical features of this rock type, one of the most crucial is the mechanical strength loss due to elevated temperatures. The study of thermal effects on rock properties is an emerging area of research with publications on the thermal behavior of several lithologies, including limestone [7][8][9], sandstone [10,11], and granite [12][13][14]. Besides the mechanical changes, mineralogical changes and other physical transformations are linked to increasing temperature in rocks such as granite [15,16] or especially carbonate rocks such as limestone [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Physical Alteration and Color Change of Granite Subjected to High Temperature

2021

View full text Add to dashboard Cite

Cylindrical specimens obtained from the monzogranite host rock of the National Radioactive Waste Repository of Hungary were tested at room temperature and 250 °C, 500 °C, and 750 °C of heat treatment. Reflectance spectra (color), bulk density, Duroskop surface hardness, and ultrasound-wave velocity values were measures before and after thermal stress. According to CIE L*a*b* colorimetric characteristics, the specimens’ color became brighter and yellower after the heat treatment. At 750 °C, a significant volume increase was recorded linked to the formation of macro-cracks, and it also led to the drop in bulk density. Smaller temperature treatment (250 °C) caused a minor decrease in density (−1.3%), which is higher than the reduction of density at 500 °C (−0.8%). Duroskop surface strength showed a slight decrease until 500 °C, and then a drastic decline at 750 °C. P- and S-wave velocity values tend to decrease uniformly and significantly from room temperature to 750 °C. P-wave velocity and Duroskop values have a high exponential correlation at elevated temperatures. Physical alterations originated from the differential thermal-induced expansion of minerals, the formation of micro-cracks. Mineralogical changes at higher temperatures also contribute to the volume change and the loss in strength.

show abstract

Mechanical properties of Beishan granite under complex dynamic loads after thermal treatment

Cited by 39 publications

References 31 publications

Heat-related Changes of Density, P-wave Velocity, and Surface Hardness of Granite

Heat-related Changes of Density, P-wave Velocity, and Surface Hardness of Granite

Degradation of Mechanical Behavior of Sandstone under Freeze-Thaw Conditions with Different Low Temperatures

Physical Alteration and Color Change of Granite Subjected to High Temperature

Contact Info

Product

Resources

About