Experimental Study of the Effect of High Temperature on the Mechanical Properties of Coarse Sandstone

Sijiang Wei,Chengdong Su,Yushun Yang,Hao Wang,Syabilla Rachmadina Cardosh

doi:10.3390/app9122424

Abstract

In order to study the effect of high temperature on the mechanical properties of rock, two groups of coarse sandstone samples were subjected to the uniaxial compression and triaxial compression test at room temperature of 25 °C and high temperatures of 100~1000 °C. The study comes to some conclusions: (1) With the increase of temperature, the longitudinal wave velocity gradually decreases, and the damage factor of temperature gradually increases. (2) For uniaxial compression tests at different temperatures, the high temperature action within 500 °C has a strengthening effect on the compression strength, and the high temperature effect has a weakening effect on the compression strength when temperatures exceed 500 °C; so 500 °C is the temperature threshold. (3) For triaxial compression tests at different temperatures, the rock strength is positively correlated with temperature and confining pressure when the temperature is lower than 800 °C and the confining pressure is lower than 15 MPa; the rock strength is negatively correlated with temperature and confining pressure when the temperature is over 800 °C and confining pressure is above 15 MPa, so 800 °C is the temperature threshold, and 15 MPa is the confining pressure threshold. (4) In the triaxial compression, the actual fracture angle of the sample after high temperature is basically the same as the theoretical calculation value, high temperature has little effect on the actual fracture angle of the sample, and the actual fracture angle is negatively correlated with the confining pressure.

Highlights

With the development of nuclear waste disposal, underground coal gasification, geothermal resource, coal mine gas explosion, underground engineering, fire reconstruction, and high temperatureAppl
(4) In the triaxial compression, the actual fracture angle of the sample after high temperature is basically the same as the theoretical calculation value, high temperature has little effect on the actual fracture angle of the sample, and the actual fracture angle is negatively correlated with the confining pressure
We carried out uniaxial compression and triaxial compression tests of two sets of samples by applying a temperature of 25 ◦ C and a high temperature of 100~1000 ◦ C, and obtained some meaningful conclusions

Summary

Introduction

With the development of nuclear waste disposal, underground coal gasification, geothermal resource, coal mine gas explosion, underground engineering, fire reconstruction, and high temperatureAppl. A lot of experimental studies and theoretical discussions on physical and mechanical parameters of rock were done by domestic and foreign scholars, which include the deformation mechanism, rock failure criterion, constitutive relation, and thermal cracking and rock damage mechanism under high temperature. He et al [1] studied the fracture density and cracking mechanism of sandstone after high temperature. Wu et al [4,5,6] studied the mechanical properties and acoustic emission of sandstone and granite after high temperature. Brotóns et al [9]

Results

Discussion

Conclusion