1. Dr. Younis M. ALSHKANE and Dr. Serwan Kh. RAFIQ
MECHANICAL PROPERTIES OF CEMENT MORTAR BY USING POLYETHYLENE TEREPHTHALATE FIBER
By Mr. Hemn U. Ahmed BOINY
Dr. Younis M. ALSHKANE and Dr. Serwan Kh. RAFIQ
©2016

2. OUTLINE INTRODUCTİON EXPERİMENTAL PROGRAM TEST PROCEDURES
RESULTS AND DİSCUSSİONS
CONCLUSİONS

3. INTRODUCTION
In Iraq, it has a wide range area of waste plastics especially those that daily used such as plastic bottles.
The main reason of this study was to investigate the effect of the utilization of PET fibers on the mechanical properties of cement mortar.

4. EXPERIMENTAL PROGRAM MATERİALS Ordinary Portland Cement
Locally River Fine Aggregate
PET Fiber
Water
Long PET fiber
Short PET fiber

5. TEST PROCEDURES COMPRESSIVE STRENGTH SPLITTING TENSILE STRENGTH
Ø50×100 mm cylinder specimens.
Samples have been tested at 7 and 28 days in accordance with ASTM C
SPLITTING TENSILE STRENGTH
Samples have been tested at 7 and 28 days in accordance with ASTM C
ULTRASONIC PULSE VELOCITY
Samples have been tested at 7 and 28 days in accordance with ASTM C
SCHMIDT HAMMER
Samples have been tested at 7 and 28 days in accordance with ASTM C805 / C805M-13 .

6. RESULTS AND DISCUSSIONS Compressive Strength
The Table 1, shows that the fibers incorporation does not increase the magnitude of the mortar compressive strength, while with decreasing the PET fiber length from 16.0 mm to 8.0 mm the mortar compressive strength is increased by 15% at 28 day tests.
The compressive strength of the cement mortar without fibers increased around 35% at 28 days, by adding 0.5% of the fiber content to the total dry weight of the mix, it decreases 8.0% of the mortar compressive strength, while by adding 3.0% of the fiber content, decrease the mortar strength by 100%.
Table 1: Mortar uniaxial compression strength (UCS) [Mpa]
Fiber Length (mm)
16.0mm
8.0 mm
Fiber Content %
0.5
1.0
1.5
2.0
3.0
Compressive Strength (7 day)
32.4
30.1
26.2
26.9
24.5
19.5
27.0
Compressive Strength (28 day)
43.5
40.3
34.9
30.3
28.8
21.6
34.8

7. RESULTS AND DISCUSSIONS Splitting Tensile Strength
In Table 3, it is clearly appeared that splitting tensile strengths of the cement mortars were increases of about 18% by adding 0.5% of the PET fiber, in comparison with the control sample, this is a desirable result that a mortar with more ductile behavior can be obtained by using waste PET fibers.
when decreasing the PET fiber length from 16.0 mm to 8.0 mm the mortar splitting strength is decrease by 6% at 28 day tests.
Table 2: Mortar Splitting Tensile Strength (STS) [Mpa]
Fiber Length (mm)
16.0mm
8.0 mm
Fiber Content %
0.5
1.0
1.5
2.0
3.0
Splitting Tensile Strength (7 day)
2.54
3.11
2.19
1.99
2.13
2.15
Splitting Tensile Strength (28 day)
3.01
3.55
2.75
3.07
2.23
2.73
2.90
Ratio of (STS/UCS)
0.07
0.09
0.08
0.10
0.13

8. RESULTS AND DISCUSSIONS Ultrasonic pulse velocity
From Fig. 1 it is noted that the speed of sound (P-wave) is higher for mortar which contains a low percentage of waste PET fibers. Also, it is noted that the waste PET fiber mortars compactness decreases which decreases the speed of sound.
Fig.1 Ultrasonic Pulse Velocity of Hardened Cement Mortar

9. RESULTS AND DISCUSSIONS Schmidt Hammer
From Fig.2 it is noted that the rebound number is a little bit higher for cement mortar which contains a low percentage of PET fiber, which is the case of the reference concrete (0% waste). It is noted that the incorporation of waste plastic fibers decrease the hardness of the surface of the cement mortar compactness which decreases the speed of sound.
Fig.2 Rebound Number (RN) of Hardened Cement Mortar

10. RESULTS AND DISCUSSIONS Stress–Strain Relationship
From Fig.3 it can be seen that with increasing the percent of PET fibers the stiffness of the mortar decreased which increases the ductility of mortar as well as improves the post-failure behavior.
Fig.3 Stress–Strain Relationship of Hardened Cement Mortar in 28 day

11. USEFUL CORRELATIONS
Fig.4 Correlations of Uniaxial Compressive Strength and tensile strength with Pulse Velocity
Fig.5 Correlations of Uniaxial Compressive Strength and tensile strength with Schmidt number (RN)

12. CONCLUSIONS
Inclusion of plastic fibers in mortar decreases slightly the Uniaxial Compressive Strength (UCS).
The splitting tensile strength was only increased for samples contained 0.5 % of fibers by 18 %
The rebound number of samples contained a low percentage of PET fibers was slightly higher than that of a high percentage of fibers.
Uniaxial compressive strength was successfully correlated with P- wave velocity and Schmidt number for cement mortar of different ages and percentages of plastic fibers using simple regression analysis.

13. Thank You