Uniaxial compressive strength and failure characteristics of arkosic sandstone after thermal treatment
2019
Experiments were conducted to study the mechanical characteristics of
arkosic sandstones sampled from Pingyi, China. Rock samples were
all thermally treated under the temperature ranging from room temperature to
800°C. Results show that as the treatment temperature rises, the
arkosic mineral composition does not change obviously, but the mechanical
behaviors change regularly. Variation trend changes dramatically at 200°C,
400°C and 500°C. With thermal expansion of mineral particles being the
dominant factor, mechanical behaviors barely change below 200°C. When
temperature ranges from 200°C to 400°C,it has an important effect on the
mechanical properties because of the thermal fracture. From 400oCto 500oC,
mechanical properties change dramatically as a result of the mutual influence
of thermal fracture, fusion and recrystallization, but the thermal fracture
is the leading factor. Because of the fusion and recrystallization,
fractures are partly filled, which results in partial recovering of the
mechanical strength. With the combined action of thermal fracture, fusion
and recrystallization after 600°C, mechanical performance of arkosic
sandstones degrades rapidly. Generally, the porosity and peak strain of arkosic
sandstones increase with the temperature rising. However, the peak stress,
elastic modulus and deformation modulus decrease simultaneously. Influenced
by mineral particles’ thermal expansion, thermal fracture, fusion, and
recrystallization and so on, the variation trend and amplitude are not the
same at different temperature ranges, and the damage mechanism of sandstones
also makes a difference.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
9
References
2
Citations
NaN
KQI