PSI - Issue 70

R. Ashwathi et al. / Procedia Structural Integrity 70 (2025) 424–431

427

Table 2. Split tensile strength of concrete Specimen 7 D (N/mm²) 14D (N/mm²)

28 D (N/mm²)

7 D (N/mm²)

14D (N/mm²)

28 D (N/mm²)

Specimen

Controlled

2.62

2.94 3.12 3.26 2.92 2.76 2.38 2.24 2.16 1.34

3.26 3.34 3.52 3.12 3.06 3.12 3.04 2.86 2.42

SF - 10% 2.34 SF - 20% 2.48 SF - 30% 2.24 SF - 40% 2.16 FA - 10% 1.09 FA - 20% 1.04 FA - 30% 1.08 FA - 40% 1.04

MK -10% 1.36 MK -20% 1.42 MK -30% 1.28 MK -40% 1.2 RHA - 10% 1.18 RHA - 20% 1.02 RHA - 30% 1.08 RHA - 40% 1.12

2.9

3.86 3.92 3.64 3.28 3.14 3.02 2.94

2.94 2.74 2.44 2.42 2.28 2.14 2.26

2.74 The strength gain observed is due to the improved adhesion between aggregates and the cement paste, thereby reducing the potential for tensile cracking. 2.3. Flexural strength of concrete The incorporation of these supplementary materials improves the flexural performance through reducing the microcracks and denser matrix. (K.M et al., 2025). The corresponding strength results of different cementitious materials are shown in Table.3

Table 3. Flexural strength of concrete Specimen 7 D (N/mm²)

14D (N/mm²)

28 D (N/mm²)

7 D (N/mm²)

14D (N/mm²)

28 D (N/mm²)

Specimen

Controlled

3.72

4.26 3.34 3.46 3.92 3.64 3.08 3.04 2.98 2.86

4.65 4.52 4.71 4.48 4.12 4.02 3.98 3.82 4.6

SF - 10% 3.24 SF - 20% 3.25 SF - 30% 3.34 FA - 10% 1.42 FA - 20% 1.38 FA - 30% 1.32 FA - 40% 1.28 SF - 40% 3.2

MK -10% 1.44 MK -20% 1.48 MK -30% 1.42 MK -40% 1.34 RHA - 10% 1.46 RHA - 20% 1.58 RHA - 30% 1.42 RHA - 40% 1.46

3.14 3.22 3.12 2.96 3.14 3.24 3.16 3.02

4.16 4.24 4.08 3.92 4.22 4.38 4.16

4.04 These materials when included in the mix, the stress distribution becomes more effective. It aids in reducing the micro crack propagation and improved load bearing capacity (Golewski D. M., 2021).

Fig. 2. Comparison on strength of concrete The controlled concrete shows a steady incline in the Fig.2 over ages and serves as a baseline for the interpretation. The addition of cementitious materials enhances the strength of concrete, particularly delivers the enhanced outcome