Issue 64

D. Derdour et alii, Frattura ed Integrità Strutturale, 64 (2023) 31-50; DOI: 10.3221/IGF-ESIS.64.03

 M M

w d



W

x 100

(1)

abs

M

d

W abs : Water absorption (%) M w : Wet mass (g) M d : Dry mass (g)

Characteristics

Units

Values

Diameter

mm mm

0.40 - 0.50

Length

1.2

1.58 0.28

Absolute density Apparent density

g/cm 3 g/cm 3

Water Absorption at 5 min Water Absorption at 24 hours

% %

60

110.57

Tensile strength

MPa mm GPa

94.73

Elongation at crack elasticity modulus

9.13 2.05

Table 8: Characteristics of date palm fibers used.

Compositions

Cellulose

Hemicellulose

Lignin

Ash

Proportions (%)

32 – 35.8

24.4 – 28.1

26.7 – 28.7

7

Table 9: Chemical composition of Date Palm fiber mesh [19]. The result on the water absorption kinetics of date palm fibers presented in Fig. 6 is similar to those found by [35,36]. The fibers have two absorption phases: The first has a fairly high slope, which characterizes the initial water absorption, corresponding to the filling of the largest pores. After 5 minutes of total immersion under water, an absorption coefficient of 63.58% was noted. The second absorption phase with a low slope corresponds to the filling of the smallest pores. The water absorption coefficient was 110.67% after 24 hours of preservation of the date palm fibers under water. However, total saturation was not reached, the fibers were kept under water at 48, 72 and 96 hours corresponding to 115.14%, 121.53% and 126.29 % water absorption coefficients respectively. This absorption capacity of date palm fibers is due to their porous structure as shown in Fig. 7.

120

100

80

60

40

Water absorption (% )

20

0

0

1

2

3

4

5

Time (h 1/2 )

Figure 7: Water absorption kinetics of date palm fibers.

37