Application of Impact Imaging Method on Nondestructive Detection of Void Defects in Sandwich-Structured Immersed Tunnel

Table 3

Material parameters.

Materials	Cement	Fly ash	Slag	FA	Coarse aggregate		Water	Plasticizer
Specifications	P II42.5	Level I	S95	Medium	(5–10 mm)	(10–20 mm)	Tap water	Polycarboxylate
Production	CR Cement	Jianbi	Caofeidian	Dongjiang	Panlong stone field		—	Sobute