Mode I Fracture Toughness Test and Fractal Character of Fracture Trajectory of Red Sandstone under Real-Time High Temperature

Table 2

Fracture toughness values of sandstone at various temperatures.

Temperature (°C)	#1	#2	#3	#4	#5	#6	Mean	Standard deviation
20	4.05	3.42	4.08	3.62	3.91	3.29	3.73	0.34
100	4.19	4.46	4.69	4.17	4.08	4.06	4.27	0.25
200	4.05	4.09	3.46	3.97	3.69	3.80	3.84	0.24
300	3.40	3.30	3.90	3.28	3.87	3.72	3.58	0.28
400	2.78	3.08	2.49	3.21	2.20	2.57	2.72	0.38
500	1.57	1.29	1.35	1.41	1.15	1.19	1.33	0.16
600	0.81	1.25	0.89	1.02	1.18	0.80	0.99	0.19
700	0.15	0.12	0.17	0.26	0.14	0.25	0.18	0.06