PSI - Issue 70

Ragupathi V. et al. / Procedia Structural Integrity 70 (2025) 548–555

552

Fig.3. (a) Slump test; (b) Compaction factor test

4.2 Mechanical Properties The mechanical properties of the modified concrete blends were improved following the incorporation of bagasse ash, foundry sand, and steel fibres, as demonstrated in Table 3. The compressive strength test results for a variety of concrete mixtures are illustrated in Figure 4. The mix CC exhibited a compressive strength of 29.2 MPa after 28 days. The addition of bagasse ash and waste foundry sand increased the BF mix's strength to 31.2 MPa, indicating a 6.84% improvement over the CC. The incorporation of steel fibres (BWFRC composites) resulted in a progressive enhancement of strength. The ultimate compressive strength of the BWFRC3 blend (1.0% steel fibre) was 38.10 MPa at 28 days, indicating a 30.48% enhancement compared to conventional concrete (CC). A minor reduction in strength (36.46 MPa) was noted when the fibre content above 1.0% (BWFRC4 blend, 1.2% steel fibre). In a similar way the split tensile strength increased from 3.12 MPa to 4.33 MPa, and the flexural strength ranged from 4.50 MPa to 5.90 MPa after 28 days. BWFRC3 exhibited the highest values. Based on IS 13311 (Part 1):1992, the UPV values ranged from 4.080 to 4.652 km/s, indicating acceptable to excellent concrete quality. The positive effects were attributed to the improved interfacial bonding within the matrix and the crack-bridging effect of steel fibres (Błaszczyński et al.,2015). The optimal composition in terms of mechanical properties was identified as BWFRC3.

Table.3. Summary of test findings on mechanical properties Mix ID Compressive Strength (MPa)

Split Tensile Strength (MPa)

Flexural Strength (MPa)

UPV (km/s)

Concrete quality grade

7days

14days

28days

28 days

CC BF

18.5 19.8 21.2 22.8 24.9 23.5

24.8 26.5 28.3 30.1 32.5 31.2

29.2 31.2 32.56 34.81 38.10 36.46

3.12 3.45 3.67 3.94 4.33 4.10

4.50 4.85 5.12 5.48 5.90 5.65

4.080 4.235 4.350 4.524 4.652 4.590

Good Good Good

BWFRC1 BWFRC2 BWFRC3 BWFRC4

Excellent Excellent Excellent

Fig.4. Comprehensive strength of various mixes