An Experimental Study on the Microstructures of Cemented Paste Backfill during Its Developing Process

Table 3

Main physical properties of P.O. 32.5 Portland cement.

Items	Value	Reference
Fineness (<0.045 mm) (%)	11.00	≤30
Initial setting time (min)	162.00	≥45
Final setting time (min)	203.00	≤390
28-day flexural strength (MPa)	6.60	6.5
28-day uniaxial compressive strength (MPa)	31.50	32.5

Note: reference of P.O. 32.5 Portland cement is from China’s cement strength classification.