PSI - Issue 67

I. Flores-Vivián et al. / Procedia Structural Integrity 67 (2025) 80–89 Ismael Flores-Vivián/ Structural Integrity Procedia 00 (2024) 000 – 000

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stripped of their formwork and stored wrapped in plastic film. The hydration of the pastes was stopped at the ages of 3 and 7 days by placing the samples immersed in acetone for 2 h, after which they were dried in the oven at 40°C for 24 h. They were then prepared for the FT-IR and SEM analysis.

Table 5. Dosage of materials for the synthesis of geopolymers (kg/m 3 )

Paste

R7

R10

R12

ZN7

ZN10

ZN12

ZY7

ZY10

ZY12

Molarity

7

10

12

7

10

12

7

10

12

MK

1246.6 1210.4 1187.5 1240.4 1204.4 1181.5 1240.4 1204.4 1181.5

NaOH

97.7

135.5 233.0 338.9

159.5 228.5 332.5

97.7

135.5 233.0 338.9

159.5 228.5 332.5

97.7

135.5 233.0 338.9

159.5 228.5 332.5

Na 2 SiO 3

239.9 349.1

239.9 349.1

239.9 349.1

H 2 O

ZN

- -

- -

- -

6.2

6.1

5.9

-

-

-

NaY

-

-

-

6.2

6.1

5.9

3. Results 3.1. Zeolite NaY

A NaY faujasite was produced following a production process that resulted in an amorphous product, which was confirmed by XRD analysis. The diffractogram obtained is shown in Figure 5, in which a hump or halo characteristic of the amorphous precursors of faujasite-type zeolites can be seen, which is centered between angles 27° and 29° at 2 θ . These amorphous materials precursors of zeolites may contain "quasicrystalline" particles, which according to the research of Provis et al., like nanocrystalline zeolites with sizes smaller than 10 nm, they are not detected as discrete peaks in XRD (Provis, Lukey, & Deventer, 2005). The chemical composition of the zeolite NaY was obtained by XRF. Table 6 shows the percentages of the components expressed as oxides. The main components were SiO 2 , Al 2 O 3 , and Na 2 O.

Figure 5. X-ray Diffractogram of Zeolite NaY

Table 6. Chemical Composition of Zeolite NaY

Oxides

SiO 2

Al 2 O 3

Na 2 O

Fe 2 O

CaO Ag 2 O K 2 O

TiO 2

Others

% 81.397 4.202 11.648 0.335 0.550 0.319 0.107 0.564 0.878