Characteristics of Recycled Polypropylene Fibers as an Addition to Concrete Fabrication Based on Portland Cement

Abstract

High-performance concrete has low tensile strength and brittle failure. In order to improve these properties of unreinforced concrete, the effects of adding recycled polypropylene fibers on the mechanical properties of concrete were investigated. The polypropylene fibers used were made from recycled plastic packaging for environmental reasons (long degradation time). The compressive, flexural and split tensile strengths after 1, 7, 14 and 28 days were tested. Moreover, the initial and final binding times were determined. This experimental work has included three different contents (0.5, 1.0 and 1.5 wt.% of cement) for two types of recycled polypropylene fibers. The addition of fibers improves the properties of concrete. The highest values of mechanical properties were obtained for concrete with 1.0% of polypropylene fibers for each type of fiber. The obtained effect of an increase in mechanical properties with the addition of recycled fibers compared to unreinforced concrete is unexpected and unparalleled for polypropylene fiber-reinforced concrete (69.7% and 39.4% increase in compressive strength for green polypropylene fiber (PPG) and white polypropylene fiber (PPW) respectively, 276.0% and 162.4% increase in flexural strength for PPG and PPW respectively, and 269.4% and 254.2% increase in split tensile strength for PPG and PPW respectively).

Properties of Alkali-Resistant Glass Fiber Reinforced Coral Aggregate Concrete

“…The whole mixing time lasts about 6 min. The mixing process in the present study is similar to that by Małek et al [29]. When the fiber volume fraction attains 2%, it is found that some difficulty is encountered more or less during the mixing process.…”

“…The CAC with no fiber reinforcement is adopted as the control concrete. Moreover, Małek et al [29] pointed out that the workability of fresh concrete becomes weaker as the fiber content increases. Because the fiber content varies in a relatively wide range in the present study, different superplasticizer additions are needed in order to ensure the slump of all the fresh concrete almost invariable.…”

“…Researchers have attempted to introduce carbon fibers [26], polypropylene fibers [26], sisal fibers [26], and basalt fibers [27,28] into CAC. As the plastic waste is efficiently recycled, Małek et al [29] successfully added recycled polypropylene plastic fibers in concrete and Kim et al [30] introduced recycled PET (polyethylene terephthalate) fibers. The results show that the compressive strength, splitting tensile strength, and modulus of rupture are increased with the fiber content, which varies in a certain range [26][27][28][29], and the permeability and shrinkage are reduced [30].…”

“…As the plastic waste is efficiently recycled, Małek et al [29] successfully added recycled polypropylene plastic fibers in concrete and Kim et al [30] introduced recycled PET (polyethylene terephthalate) fibers. The results show that the compressive strength, splitting tensile strength, and modulus of rupture are increased with the fiber content, which varies in a certain range [26][27][28][29], and the permeability and shrinkage are reduced [30]. Moreover, glass fibers have been used in civil engineering since the late 1960's [31].…”

Effect of Waste Glass Addition as a Replacement for Fine Aggregate on Properties of Mortar

“…Therefore, there is a need to look for materials as a replacement for cement or aggregate. Recycled materials are used to limited energy consumption by the concrete industry and the production of concrete as an environmentally friendly material [ 7 , 8 , 9 , 10 ]. The use of fly ash as a replacement for cement was studied by many researchers [ 11 , 12 , 13 , 14 , 15 ].…”