Fracture Characteristics of Polyurethane Grouting Materials Based on Acoustic Emission Monitoring

Table 1

Orthogonal test scheme of three factors and four levels (L16).

Level	Factors
	Polyether polyols a : b	Catalysts A33	Surfactants BL-8468
1	9 : 11	0.5	0.5
2	10 : 10	0.8	0.6
3	11 : 9	1.0	0.7
4	8 : 12	1.2	0.8