PSI - Issue 70

Janani P.K. et al. / Procedia Structural Integrity 70 (2025) 525–532

530

4g

2724.48

Acid Resistance (% Strength Loss)

0g

29.6

4g

16.9

Acid Resistance (% Weight Loss)

0g

3.90

4g

1.73

3.4 Microstructural and Spectroscopic Findings The analysis through SEM-EDX showed that PET- SiO₂ integration produced a dense geopolymer matrix which lead to reduced microvoids and strengthened inter-particle bonding. The PET- SiO₂ 4g mixture developed the most dense microstructure because it strengthened the interfacial transition zone which improved material strength and resilience.

Fig.5. SEM-EDX Analysis of PET- SiO₂ Geopolymer Matrix

The results from EDX elemental mapping analysis showed that PET modification led to higher carbon concentrations which indicated successful integration of PET- SiO₂ within the samples. The geopolymer framework maintained chemical stability through stable oxygen and sulfur content as well as minor Na and Si level reductions.

Fig. 6. SEM-EDX Elemental Composition Overlay (a) Elemental mapping of PET- SiO₂ -modified concrete, (b) Intensity distribution of key elements.