PSI - Issue 73

Sushant Chaudhary et al. / Procedia Structural Integrity 73 (2025) 19–26 Pratanu Ghosh / Structural Integrity Procedia 00 (2025) 000–000

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y = 10.89ln(x) - 19.69 y = 11.9ln(x) - 27.5 y = 8.97ln(x) - 16.83

y = 6.22n(x) - 1.21 y = 9.21ln(x) - 17.35 y = 11.52ln(x) - 18.98

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Compressive Strength (MPa)

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Equivalent age (hrs) 100 TII-V 90 TII-V/ 10 Z 85 TII-V/15 Z 80 TII-V/ 20 Z 75 TII-V/ 25 Z 70 TII-V/ 30 Z

Figure 3: Arrhenius maturity function for all binary mixtures

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00

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Estimated Compressive Stength (MPa)

Actual Compresiive Strength (MPa)

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Lineární (10% error)

Lineární (20% error)

Figure 4: Actual vs. Estimated Compressive Strength using S-M Relationship (Logarithmic) for all mixtures

The obtained best-fit equation was logarithmic. The strength estimation for all the mixtures was within 20% of the actual strength, with most of the error within 10%, as shown in Figure 4. This validates the accuracy and reliability of the maturity method for the strength estimation of zeolite-based mixtures. TTF and Equivalent age methods helped in strength prediction with almost equal accuracy. This can be credited to using only one temperature (room temperature) for the research analysis. However, the Arrhenius function provided slightly better prediction values than the Nurse-Saul function. 4.2. Datum Temperature and Activation Energy The activation energy and datum temperature values were calculated using “Solver” in Excel to fit the strength maturity curve best. The optimum activation energy (Q-value) values for all the binary and ternary mixtures were between 34000 J/mol and 39000 J/mol. An average value of 37500 J/mol was adopted to calculate maturity functions for all mixtures. The effect of using an average Q-value instead of a mix-specific optimum Q-value is minimal. It is shown in Table 2 for the mixture with the most significant discrepancy, i.e., 90 TII-V/ 10 Z. On the other hand, the value for optimum datum temperature obtained from “Solver” was 0 0 C (32 0 F) for all the binary and ternary mixtures.