Mechanical Behavior of Recycled Pet Fiber Reinforced Concrete Matrix

Authors: Comingstarful Marthong, Deba Kumar Sarma

Abstract:

Concrete is strong in compression however weak in tension. The tensile strength as well as ductile property of concrete could be improved by addition of short dispersed fibers. Polyethylene terephthalate (PET) fiber obtained from hand cutting or mechanical slitting of plastic sheets generally used as discrete reinforcement in substitution of steel fiber. PET fiber obtained from the former process is in the form of straight slit sheet pattern that impart weaker mechanical bonding behavior in the concrete matrix. To improve the limitation of straight slit sheet fiber the present study considered two additional geometry of fiber namely (a) flattened end slit sheet and (b) deformed slit sheet. The mix for plain concrete was design for a compressive strength of 25 MPa at 28 days curing time with a watercement ratio of 0.5. Cylindrical and beam specimens with 0.5% fibers volume fraction and without fibers were cast to investigate the influence of geometry on the mechanical properties of concrete. The performance parameters mainly studied include flexural strength, splitting tensile strength, compressive strength and ultrasonic pulse velocity (UPV). Test results show that geometry of fiber has a marginal effect on the workability of concrete. However, it plays a significant role in achieving a good compressive and tensile strength of concrete. Further, significant improvement in term of flexural and energy dissipation capacity were observed from other fibers as compared to the straight slit sheet pattern. Also, the inclusion of PET fiber improved the ability in absorbing energy in the post-cracking state of the specimen as well as no significant porous structures.

Keywords: Concrete matrix, polyethylene terephthalate (PET) fibers, mechanical bonding, mechanical properties, UPV.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1108701

References:

[1] S. B. Kim, N. H Yi, H.Y. Kim, JHJ.Kim, and Y. C. Song, “Material and structural performance evaluation of recycled PET fiber reinforced concrete,” Cement & Concrete Composites, vol. 32, pp. 232-240, 2010.
[2] D. Foti, “Preliminary analysis of concrete reinforced with waste bottles PET fibers,” Construction and Building Materials, vol. 25, no. 4, pp. 1906–1915, 2011.
[3] D. Foti, “Use of recycled waste pet bottle fibers for the reinforcement of concrete,” Composites Structures, vol. 96, pp. 396-404, 2013.
[4] L. A. Pereira de Oliveira, J. P. Castro-Gomes. “Physical and mechanical behavior of recycled PET fiber-reinforced mortar,” Construction and Building Materials, vol. 25, no. 4, pp. 1712–1717, 2011.
[5] I. S.12269., “Specification for OPC-53 Grade cement,” Bureau of Indian Standard, New Delhi, 1987.
[6] I. S. 2386, “Methods of test for aggregates for concrete - Part 1: Particle size and shape,” Bureau of Indian Standard, New Delhi, 1963.
[7] I. S. 2386, “Methods of Test for Aggregates for concrete - Part 3: Specific Gravity, Density, Voids, Absorption and Bulking,” Bureau of Indian Standard, New Delhi, 1963.
[8] ACI 544.1 R-96, “State-of-the-Art Report on Fiber Reinforced Concrete Reported by ACI Committee 544,” 2002.
[9] I. S. 1199, “Methods of sampling and analysis of concrete,” Bureau of Indian Standard, New Delhi, 1959.
[10] I. S. 516, “Method of Tests for Strength of Concrete,”Bureau of Indian Standard, New Delhi 1959 (Reaffirmed 2004).
[11] I. S. 5816, “Method of Test Splitting Tensile Strength,” Bureau of Indian Standard, New Delhi, 1999.
[12] I. S. 13311-1, “Method of Non-destructive testing of concrete, Part 1: Ultrasonic pulse velocity,” Bureau of Indian Standard, New Delhi, 1992.