Issue 66

S.E. Daguiani et alii, Frattura ed Integrità Strutturale, 66 (2023) 88-111; DOI: 10.3221/IGF-ESIS.66.05

GGBS) and replacement of 30 % of cement, as shown in Fig. 5. In light of this, we must consider a mixture design with three factors taken in mass proportions (PC %, WGP %, and GGBS %). Mixture proportions Understanding the role of the different factors (PC, WGP, and GGBS contents) separately on pastes properties is the goal target of the present work. The Sum of concentrations achieves the following relationship:

(2)

%PC+%WGP+%GGBS=100%

The total number of experiments was determined using the following equation:       f +l -1 ! N= l ! f -1 !

(3)

where: ( f ) is the number of factors and ( l ) is the number of levels. The combination number treated was (C=15) based on four levels and three factors to determine the impact of these factors on the characteristics of pastes. The positions of the 15 mixtures on the ternary diagram are depicted in Fig. 6. The statistical model used to describe the variation of the measured values is a second-degree polynomial in the dependent variables PC, WGP, and GGBS. This model can be expressed in the form :

    ( ) ) Y X PC X WGP X GGBS X PCWGP X PC GGBS X WGP GGBS            1 2 3 12 ( ) ( ) ( ( ) (



)

(4)

13

23

where: (Y) is the expected response and (X 1 , X 2 , X 3 , X 12 , X 13 , X 23 ) are the model coefficients.

5 0

1

0,1

0,9

0,2

0,8

4

9

0,3

0,7

0,4

0,6

12 0,5

0,5

3

8

0,6

0,4

0,7

0,3

2

7

11

14

0,8

0,2

0,9

0,1

1

0

1 1

6

10 0,5

13

15

0,9

0,8

0,7

0,6

0,4

0,3

0,2

0,1

0

PC

Figure 6: Triangular representation of the 15 mixtures according to PC, WGP, and GGBS dosage.

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