PSI - Issue 70

Rupankar Chakraborti et al. / Procedia Structural Integrity 70 (2025) 279–286

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The following discussions will be based on 14-days pond curing. The compressive strength values for control mix CM40 (target strength 40 MPa) possess strength values of 33.67 MPa as the mean strength(84.2% target strength achieved).Dissimilar trend is observed for CM40/BFS20/SF5 (specimen with 20% GGBFS and 5% SF replacement b/w of cement), CM40/BFS30/SF10 (specimen with 30% GGBFS and 10% SF replacement b/w of cement), CM40/BFS40/SF15 (specimen with 40% GGBFS and 15% SF replacement b/w of cement).For the specimen CM40/BFS20/SF5, the mean compressive strength is obtained as 34.92 MPa, achieved 87.30% of the target strength. The specimen CM40/BFS30/SF10 achieved a mean compressive strength of 35.70 MPa, hence achieving 89.25% of target strength. The specimen CM40/BFS40/SF15 achieved strength of 34.81 MPa i.e., achieving 87% of target strength. Table 7. Compressive strength on 14 days curing SPECIMEN COMPRESSIVE CUBE STRENGTH(MPa) DESIGNATION (Age of curing – 14 days) %BFS+ %SF Spec1 Spec2 Spec3 Mean CM40/BFS0/SF0 0 33.9 34.0 33.2 33.7 CM40/BFS20/SF5 25 35.0 34.7 35.1 34.9 CM40/BFS30/SF10 40 34.2 36.0 36.9 35.6 CM40/BFS40/SF15 55 35.9 35.6 35.2 35.7 The following discussions are based on 28-days curing of normal mix and cement replaced sample mix. The compressive strength values for control mix CM40 (target strength 40 MPa) possess strength values of 3 6.96 MPa as the mean strength(92.41% target strength achieved).Dissimilar trends were observed for CM40/BFS20/SF5(specimen with 20% GGBFS and 5% SF replacement b/w of cement), CM40/BFS30/SF10 (specimen with 30% GGBFS and 10% SF replacement b/w of cement), CM40/BFS40/SF15 (specimen with 40% GGBFS and 15% SF replacement b/w of cement).For the specimen CM40/BFS20/SF5, the mean compressive strength was obtained as 38.18 MPa, achieved 95.45% of the target strength. The specimen CM40/BFS30/SF10 achieved a mean compressive strength of 39.96 MPa, hence achieving 99.9% of target strength. The specimen CM40/BFS40/SF15 achieved strength of 37.94 MPa i.e., achieving 94.85% of target strength.

Table 8. Compressive strength on 28 days curing SPECIMEN COMPRESSIVE

CUBE

STRENGTH(MPa)

DESIGNATION

(Age of curing – 28 days)

%BFS+ %SF

Spec1

Spec2

Spec3

Mean

CM40/BFS0/SF0

0

37.2 37.5

36.8

36.9

36.96 38.18 39.96

CM40/BFS20/SF5 25 CM40/BFS30/SF10 40 CM40/BFS40/SF15 55

38.38 39.98

38.68 39.92

40

40.7

41.2

41.5

41.1

5.1 Comparative study among the proportions

Fig.3. Compressive strength for specimens on 7 days curing Fig. 4. Compressive strength for specimens on 14 days curing