Effects of Foaming and Drainage Behavior on Structure and Properties of Polyurethane/Water Glass (PU/WG) Grouting Materials for Coal Mines

Figure 5

SEM images of the C7-1% sample: (a) 500x, (b) 1000x, (c) 3000x, and (d) 6000x.

(a)

(b)

(c)

(d)