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

Table 4

Self-compacting concrete mixes proportions.

Materials	Cement	Fly ash	Slag powder	CA1	CA2	Silica sand	Water	Plasticizer
kg	270	196	84	39	508	782	171	5.5

Note. FA: fine aggregate; CA₁: coarse aggregate (5–10 mm); CA₂: coarse aggregate (10–20 mm).