PSI - Issue 70

Suresh Kumar Verma et al. / Procedia Structural Integrity 70 (2025) 327–334

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Fig. 3. (a) SEM; (b) EDS of Nano-Alumina

• Nano-Calcium Carbonate (CaCO 3 ) Precipitated Nano-Calcium Carbonate (CaCO 3 ) with an average particle size of approximately 60 nm was used. This material functions primarily as a filler and nucleation site, improving early hydration and matrix densification. NCC also enhances workability and reduces porosity by improving particle packing. The nano-CaCO 3 was supplied in a high-purity dry powder form and stored in airtight containers to prevent moisture absorption. The SEM and EDS of Nano-Calcium Carbonate is shown in Fig. 4.

Fig. 4. (a) SEM; (b) EDS of Nano-Calcium Carbonate

• Admixture A Polycarboxylate Ether (PCE)-based high-range water-reducing admixture was employed to maintain workability, especially in mixes containing nanomaterials, which tend to reduce slump due to their high surface area. The dosage was optimized through trial mixes to achieve desired flow without segregation or bleeding. PCE is known for its strong dispersion capability and compatibility with nanomaterials. • Fine Aggregate Natural river sand conforming to IS 383:2016 was used as the fine aggregate. The sand was sieved and tested to ensure it met the Zone II grading as per IS classification. It was clean, free from clay, silt, and organic impurities, and had a fineness modulus in the range of 2.6 – 2.9. Proper gradation ensured good workability and minimized void content in the mix.