PSI - Issue 71

Sphurty Raman et al. / Procedia Structural Integrity 71 (2025) 409–416

414

3.8 4 4.2 4.4 4.6

3.5 4 4.5 5

y = 0.0133x + 3.2795 R² = 0.9021

(MPA)

(MPA)

50

60

70

80

90

100

R40G0 R40G10 R40G20 R40G25 R40G30 R40G40

SLUMP (MM) Flexural Strength (MPa) Linear (Flexural Strength (MPa))

FLEXURAL STRENGTH

MIX Flexural Strength (MPa) Estimated Flexural Strength (MPa)

FLEXURAL STRENGTH

Fig. 6 Correlation between Flexural Strength and Slump

Fig. 7 Comparison of Actual vs. Estimated Flexural Strength for Various Mix Designs

4 4.1 4.2 4.3 4.4 4.5

3.8 4 4.2 4.4 4.6

y = 0.0079x + 3.718 R² = 0.9291

(MPA)

(MPA)

50

60

70

80

90

100

R40G0 R40G10 R40G20 R40G25 R40G30 R40G40

SLUMP (MM) Split Tensile Strength (MPa) Linear (Split Tensile Strength (MPa))

MIX Split Tensile Strength (MPa) Estimated Split Tensile Strength (MPa)

SPLIT TENSILE STRENGTH

SPLIT TENSILE STRENGTH

Fig. 8 Correlation between Split Tensile Strength and Slump

Fig. 9 Comparison of Actual vs. Estimated Split Tensile Strength for Various Mix Designs

Analysis of concrete mixtures with 40% RCA and varying WGP content reveals strong correlations between slump and strength properties. Compressive strength shows a high positive correlation with slump (r = 0.97905), as do flexural (r = 0.949815) and split tensile strengths (r = 0.963893). As WGP content increases from 0% to 40%, all strength measures and workability decrease, indicating weaker cohesion in the concrete matrix. Figures 4-9 illustrate these trends, demonstrating that slump-based models can estimate strength effectively. However, the consistent decline in both strength and workability with increasing WGP content emphasizes the need for careful optimization in sustainable concrete mix designs to balance environmental benefits with performance requirements. 3.5 Regression Analysis of Mechanical Properties v/s Water Absorption (%)

30.5 31 31.5 32 32.5 33 33.5 34 34.5

y = -0.64x + 34.867 R² = 0.9764

y = -2.2248x + 52.565 R² = 0.9972

30 31 32 33 34 35

y = -0.6388x + 34.863 R² = 0.9755

MIX Compressive Strength (MPa)

8.1

8.6

9.1

9.6

10.1

Fig. 11 Comparison of Actual vs. Estimated Compressive Strength Across Mix Designs Estimated Compressive Strength (MPa) Linear (Compressive Strength (MPa)) Linear (Estimated Compressive Strength (MPa))

WATER ABSORPTION %

COMPRESSIVE STRENGTH (MPA)

COMPRESSIVE STRENGTH (MPA)

8.27 8.55 8.85 9 9.3 9.8

Fig. 10 Correlation between Compressive Strength and Water Absorption