PSI - Issue 70

R. Mohanraj et al. / Procedia Structural Integrity 70 (2025) 358–364

361

Fig. 1. Graphic Representation of effect of Nano TiO 2 on Compressive Strength

4.2. FTIR Spectroscopy Test Significant alterations in the chemical composition and molecular interactions within the cement matrix were discovered by the FTIR spectroscopy investigation of flash-based cement mortar containing nano- TiO₂ and the results were depicted in Fig. 2. Strength growth in cementitious materials is attributed to calcium silicate hydrate (C S-H) gel, which was confirmed to be enhanced by the spectrum data. It was confirmed that nano- TiO₂ actively participated in hydration reactions by the existence of significant absorption peaks between 950 cm⁻¹ and 1200 cm⁻¹, which suggested the production of C-S-H gel. The mortar with 3-4% nano- TiO₂ had the strongest intensity of these peaks, indicating ideal nucleation effects that encouraged more C-S-H gel formation. The peak intensity did, however, somewhat decrease at 5% nano- TiO₂, suggesting that too much nano - TiO₂ might have caused particle agglomeration, which would have lessened its ability to improve hydration. Nano- TiO₂ -modified samples showed a discernible decrease in the calcium hydroxide (CH) peak at around 3640 cm⁻¹, especially in the 3 -4% dose range. This reduction implies that nano- TiO₂ had a role in the pozzolanic reaction, consuming CH to create more C -S-H gel and enhancing the strength and longevity of the mortar. Since denser and more resilient mortar constructions are associated with lower CH levels, the decrease in CH content is a sign of improved cement hydration. The silicate and carbonate phases were linked to additional peaks seen in the 600 – 800 cm⁻¹ range, suggesting enhanced phase stability in cement treated with nano- TiO₂. Its integration within the cementitious matrix was confirmed by the existence of TiO₂ -related spectral bands in samples with greater nano- TiO₂ content. Higher dosages, however, caused unreacted TiO₂ peaks to emerge, suggesting that too many nanoparticles may not adequately aid in hydration at a certain point and may even cause strength loss as a result of poor dispersion.