Shear Database and Study of the Parameters Influencing Shear Behavior - On Shear Behavior of Structural Elements Made of Steel Fiber Reinforced Concrete - page 175

Table 8.27 Constant variables between the beams within the same series (size effect beams)
Constant variables
Cross-section shape: Rectangular reinforced (no prestressed) beams
No stirrups
3 point test
a/d = 3.0
Type of bers: La Gramigna © l f /d f = 62.5; l f =50mm

b w = 250 mm
ρ l (%) = 1.12
Compressive strength level assumed constant:
38.65 MPa for PC; 32.07 MPa for FRC50; 33.08 MPa for FRC75

Table 8.28 Factors and dependent variable analyzed in the ANOVA analysis of size effect beams
Factors (independent variables)
d (mm): 440, 940, 1,440
f R3 (MPa): 0, 5.00, 6.00
Codes: EHE08, MC2010, RILEM
Dependent variable
Shear safety margin (SM)

Table 8.29 Analysis of variance (ANOVA) for SM on shear — type III sum of squares (size effect)

Source of variation Sum of Squares d.f Mean square F-ratio p-value

Main effects
A: d (mm)

0.0000

0.313956 2 0.156978 409.51

B: f R3 (MPa) 0.00682222 2 0.00341111 8.90 0.0092

C: Code 0.153356 2 0.0766778 200.03 0.0000

Interactions
AB 0.141889 4 0.0354722 92.54 0.0000

AC 0.00142222 4 0.000355556 0.93 0.4939

BC 0.00988889 4 0.00247222 6.45 0.0127

Residual 0.00306667 8 0.000383333

Total (corrected) 0.6304 26
All F-ratios are based on the residual mean square error

between concrete without cant differ-

ences between the different, but MC2010 is, in this case, the safest Code.
As was seen in the ANOVA table (Table 8.29 ), in this Series two interactions
were statistically signi

bers and with f R3 = 5 MPa. There are signi

cant: d with f R3 (AB), and f R3 with Code (BC). By means of
surface charts (Figs. 8.31 , 8.32 and 8.33 ), it is possible to evaluate the in fl uence of

the interactions on the shear SM.