PSI - Issue 70

Shashikant Kumar et al. / Procedia Structural Integrity 70 (2025) 501–508

505

2.3. Fresh properties The European Guidelines EFNARC for Self-Compacting Concrete's recommended methodology was followed in order to analyse the fundamental fresh state characteristics of HVFA-SCC mixes, like filling ability, segregation resistance, passing ability, and deformability, employing the resulting quantities: slump flow, spread diameter, L-box blocking ratio, J-ring test, and V-funnel passing times. 2.4. Hardened properties The three cubical specimens of 150 × 150 × 150 mm size for each mix were subjected to compressive strength tests after 14, 28, and 56 days of water curing, in compliance with IS: 516-2021. Split tensile strength of HVFA-SCC has been evaluated on specimens of cylindrical shape with 150 mm diameter and 300 mm height after 28 days of water curing, in accordance with IS: 516-2021. 2.5. Microstructural properties The interfacial transition zone between aggregate and paste of HVFA-SCC was seen employing a scanning electron microscope (SEM). The chemical composition of HVFA-SCC mix in the transition zone was ascertained through the application of X-ray diffraction (X RD) analysis. With CoKα radiation, X -ray diffractometer CPS 120 was used to create XRD patterns. Minerals were identified by using the orientated section method on both the bulk powdered samples and the smallest fraction (˂5 μm). XRD analysis of the produ cts was used to track phase changes in the samples after calcination. Since the primary active portion of the spectra is found for 2θ angles between 5 and 45°, results are only shown for this range. 3. Results and discussion 3.1. Flowability results For each HVFA-SCC mix, the slump flow values were established and attained within the range of 750 ± 20 mm. The T-500 time decreases with the rise in FA content, indicating enhanced flowability. A significantly reduced V funnel flow duration was observed in SCC containing a large amount of FA, indicating a reduction in viscosity. Combining SF with OPC and FA binary cementitious blends makes SCC mixes more viscous. OPC, FA, and SF made up the ternary cementitious mixes of HVFA-SCC, which met the standards for EFNARC 2005 consent. T-500 vs J ring test and maximum spread diameter test results are presented in Fig. 2 which shows good correlation.

0 1 2 3 4 5 6 7 8

620 640 660 680 700 720 740 760

10 11 12 13 14

0.5 0.6 0.7 0.8 0.9 1 1.1

y = 1.5132e 0.285x R² = 0.9188

y = 7.4687e 0.0921x R² = 0.9315

y = 833.86e -0.052x R² = 0.9725

y = 1.0581e -0.052x R² = 0.928

5 6 7 8 9

J-ring test

V-funnel Test L-box Test

V-funnel test

J Ring Test Maximum Spread Diameter

L-box test

Maximum spread diameter

0

2

4

6

0

2

4

6

T-500

T-500

Fig. 3. T-500 vs V-funnel and L-box test results

Fig. 2. T-500 vs J-ring test and maximum spread diameter test results

According to the experimental results, segregation and bleeding were lessened in the SCC mixes when FA and SF were incorporated simultaneously. To make SCC mixes more viscous, silica fume was also a desirable addition. In