Synthesis and Characterization of Porous Fly Ash-Based Geopolymers Using Si as Foaming Agent

Figure 5

Optical microscope images of foamed geopolymers. (a) exp. 5 (R/Al = 0.8, Si = 0.085%); (b) exp. 6 (R/Al = 1.2, Si = 0.085%); (c) exp. 7 (R/Al = 1.6, Si = 0.085%); (d) exp. 8 (R/Al = 2.0, Si = 0.085%); (e) exp. 2 (R/Al = 1.2, Si = 0.050% w/w); (f) exp. 6 (R/Al = 1.2, Si 0.085% w/w); (g) exp. 10 (R/Al = 1.2, Si = 0.120% w/w); (h) exp. 14 (R/Al = 1.2, Si = 0.150% w/w).

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