Sampling and Mechanical Testing of Backfill in Large Mined-Out Area

Table 3

Strength test data of backfill.

No.	Middle part	Sample quantity		Sampling density (no/m)		Average strength (MPa)
		Compressive	Tensile	Compressive	Tensile	Compressive	Tensile
GZK1	-170	0	0	0	0	0	0
GZK2	-230	41	72	1.12	1.94	3.583	0.458
GZK3	-230	29	58	2.29	4.32	3.402	0.524
GZK4	-170	32	38	0.91	1.08	2.928	0.328
In total	—	102	168	—	—	—	—