PSI - Issue 55

6

Afif Rahma et al. / Procedia Structural Integrity 55 (2024) 206 – 213 Afif Rahma/ Structural Integrity Procedia 00 (2019) 000 – 000

211

0.0 1.0 2.0 3.0 4.0 5.0 6.0

4.800

3.653

3.524

3.053

2.763

(MPa)

0.911

Compression Strength

M(0)

M(0/0) M(4/2.5) M(8/2.5) M(4/5.0) M(8/5.0)

Figure 8: relation between compression strength and both length and weight

Figures 9, and 10 show that the increasing rate of compressive strength is more sensitive to the weight of the fibre than to its length. On the other hand, the rise of the length from 4 to 8 cm is insignificant contrary to the weight which can add a significant value to the resistance of the concrete. This result is confirmed by the number of fibre for M(4/5.0) and M(8/2.5) where the strength of the first is better than the second one. Thus, for better feasibility it is interesting to find the balance between weight and length to make the granular medium more homogeneous and give it better consistency.

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

4 cm 8 cm

2.5 kg 5.0 kg

(MPa)

(MPa)

Compression Strength

Compression Strength

0

2

4

6

8

10

0

1

2

3

4

5

Weight of fibers (kg/m 3 )

Length of fiber(cm)

Figure 9: Role of length of fibre

Figure 10: Role of weight of fibre

3.3. The ductility The value of the deformation was noted before the sample lost the capacity to resisting to the applied loads (Table 2). These values prove that the most important contribution of the fibre to the concrete properties is the large ductility before rupture.

5.0% 6.0% 7.0% 8.0% 9.0% 10.0%

5.0% 6.0% 7.0% 8.0% 9.0% 10.0%

(3.65 MPa)

(number of fibers)

(6594)

(rupture strength)

(3.52 MPa)

(3297)

(3.05 MPa)

(  %)

(  %)

(1648)

(2.76 MPa)

(3297)

Rupture deformation

Rupture deformation

M(4/2.5) M(8/2.5) M(4/5.0) M(8/5.0)

M(4/2.5) M(8/2.5) M(4/5.0) M(8/5.0)

Figure 11. Relation of fibres’ number and collapse deformation

Figure 12. Relation of stress and collapse deformation

The value of the collapse deformation, as shown in figure (11), depends on the length, the weight of fibres, and consequently the number of fibres; where all these factors contribute to the strength of the fibre concrete (figure 12).