Study on Modification of Alkali-Free Liquid Accelerator of Mine-Used Wet-Mix Shotcrete

Table 1

Performance requirements of the paste with the accelerator and hardened mortar.

Product grade	Initial setting time (min)	Final setting time (min)	1 d compressive strength (MPa)	28 d compressive strength ratio (%)
First grade	≤3.0	≤8.0	≥7.0	≥75
Qualified products	≤5.0	≤12.0	≥6.0	≥70