PSI - Issue 70

Abutu Simon John Smith et al. / Procedia Structural Integrity 70 (2025) 59–66

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2.08 represents a /d of 2.82 or 2.08. For example, BS/2/2.82 is described as a UHPFRC-CA beam containing straight steel fiber with 2% volume of steel fiber and a /d of 2.82. Furthermore, the UHPFRC-CA beams tested in this study were also modelled using ABAQUS and simulated using dynamic explicit analysis to validate the experimental results. The result in terms of the crack pattern and failure mode is presented in section 3.2 and Figures 4 (a-d). 3. Results and Discussions 3.1. Load-Crack Width Relationship Figure 3(a) illustrates the load-flexural crack width relationship of the beams and it revealed that the first flexural crack width of all the beams except BH/2/2.82 (with the width of 0.03mm) was 0.01mm with their corresponding loads presented in Table 3. Figure 3(b) also showed that the first shear crack of all the beams appeared with 0.01mm crack width except BS/3/2.82 that has a width of 0.02mm; and the first shear cracking loads for the beams can be seen in Table 3. More so, Table 3 also contains results like width of the flexural crack with the largest width at appearance, load at which the flexural crack with the largest width appeared, width of diagonal crack at appearance, load at which diagonal crack appeared, ultimate load of the beams, and flexural and diagonal crack widths at ultimate load.

Table 3. The different crack properties of the beam samples Beam specimen

BS/2/2.82 BH/2/2.82 BS/3/2.82 BS/2/2.08

1 st Flexural crack width (mm)

0.01

0.03

0.01

0.01

Load at which 1 st flexural crack appeared (kN)

26

28

26

24

1 st shear crack width (mm)

0.01

0.01

0.02

0.01

Load at which 1 st shear crack appeared (kN) Width of the flexural crack with the largest width at appearance (mm) Load at which the flexural crack with the largest width appeared (kN) Width of diagonal crack at appearance (mm) Load at which diagonal crack appeared (kN) Flexural crack width at ultimate load (mm) Shear crack width at ultimate load (mm)

49

51

50

52

0.05

0.03

0.01

0.03

49

74

50

52

0.01

0.01

0.02

0.01 108 2.28 3.60 360

95

97

74

0.87 1.40 273

0.11 1.60 258

0.40 1.80 283

Ultimate load (kN)

0 100 200 300 400

400

BS/2/2.82 BH/2/2.82 BS/3/2.82 BS/2/2.08

BS/2/2.82 BH/2/2.82 BS/3/2.82 BS/2/2.08

200 300

100

0

Applied load (kN)

Applied load (kN)

0

2

4

0

5

Flexural crack width (mm)

Diagonal crack width (mm)

(a) Load - flexural crack width

(b) Load - diagonal crack width

Fig. 3. Load - crack width behavior of the beams

Further analysis of Figures 3(a) and 3(b) revealed that, as the beams’ loading was continuously increased, the width of the flexural crack and diagonal crack increased slowly and linearly until the load of 233kN and 233kN respectively for BS/2/2.82, 212kN and 235kN respectively for BH/2/2.82, 242kN and 194Kn respectively for BS/3/2.82, and 304kN and 304kN respectively for BS/2/2.08. Beyond these loads, load increment led to non-linear