Experimental Study on High-Pressure Air Blasting Fracture for Coal and Rock Mass

Table 4

The length of each stage and the experimental block cracking pressure and breaking pressure.

Volume of container (L)	Vessel pressure (MPa)	Fast rising stage of pressure (ms)	Cracking pressure (MPa)	Slowly rising stage of pressure (ms)	Breaking pressure (MPa)	Pressure drop stage (ms)	Remarks
1	5	47	2.5	104	3.8	83	Gas pressure drops below 1 MPa
	7.5	65	3.5	100	5.1	303
	10	78	4.5	250	7.4	374
2	5	47	2.5	107	3.5	82
	7.5	65	3.5	104	5.1	301
	10	78	4.5	251	6.9	371
3	5	47	2.3	109	3.3	80
	7.5	65	3.5	106	4.5	300
	10	78	4.4	256	6.6	370