# Mechanical Strength Characterization of Plastic Fiber Reinforced Cement Concrete Composites
###### Abstract
A comprehensive review on the various types of wastes was conducted and the effect of various types of fibers such as PET, rubber tires, and glass was analyzed [8]. Studies were also conducted on using recycled plastic as aggregate (RPA) fillers up to 70% replacement for conventional sand and quarry dust. The test results suggested that the RPA aggregate bonding with filler materials enhanced the compressive properties, and the angular particle of quarry fines was found to provide better strength properties than normal sand fillers. The reduction in compressive strength for RPA was noted and was primarily due to weak interface properties, RPA aggregate, and cement mortar due to hydrophobic surface characteristics of the plastic aggregates [9].Three different types of recycled waste plastic have been used as partial replacement for conventional aggregates. The mechanical properties were found to be affected with large volume replacements of RPA [10]. In recent times, a most versatile technique for plastic disposal is to recycle them as shredded plastic fiber, which, in turn, is used as matrix reinforcement for concrete. Steel fibers have been typically used in many research studies due to high modulus and large tensile strength [11]. Nowadays, synthetic fibers are becoming more popular for its reinforcing ability in the production of lightweight precast concrete elements. Fiber performance improves in a concrete matrix with a maximum fiber volume fraction up to 1% [12]. With increasing fiber volume fraction, the concrete mix becomes too stiff, resulting in a harsh mix and more void formation, leading to poor concrete strength. The replacement of steel fibers with the polypropylene fibers at a rate of 0.2% by volume fraction improved the overall mechanical properties of the concrete. Many research investigations have shown that fiber pullout strength is primarily dependent on its embedment length and the volume fraction of fibers available at the crack front. [13]. Experimental investigations on metalized plastic waste (MPW) generated from discarded food packaging were analyzed in another study [14]. The MPW films were shredded into the macro fibers of varying lengths of 5 mm, 10 mm, and 20 mm and mixed into the concrete by volume fractions from 0% to 2%. The test results showed excellent improvement of the impact resistance by concrete containing MPW fibers of 20 mm length compared to the conventional concrete. In another typical study, the impact resistance of concrete composites incorporating metalized plastic fibers in palm oil fuel ash (POFA) were investigated [15]. Concrete mixes were proportioned with 20 mm plastic fibers and added up to 1.25% by volume of concrete. Test results were indicative of the improved impact resistance and strength properties of plastic fiber incorporated hardened concrete. The effect of waste plastic fibers on the behavior of self-compacting concrete was investigated to evaluate the resistance of chloride attack [16]. Test results showed the integrity of fibers in crack inhibition and thereby provide good chloride ingression into the concrete surface. Fiber addition does marginally improve the pre-peak strain hardening region with an appreciable increase in the elastic modulus. The addition of steel fibers has shown a maximum increase in compressive strength up to 15% [17]; however, an appreciable increase in bond strength and toughness was noted with the addition of steel fibers [18]. The maximum volume fraction of fibers at the crack plane plays an important role in stable crack growth formation. Many investigations have proven the beneficial addition of high modulus fiber on the overall improvement in strength, ductility, toughness, and durability [19]. The basic fiber mechanism is to prevent the crack origination and propagation. The use of high strength fibers at a large volume fraction does possess relative advantages on the flexural and tensile strength [20; 21].