Effect of PET Plastic Cut Pieces’ Aspect Ratio on Fresh and Mechanical Properties of Cement Mortar

Polyethylene terephthalate (PET) fibers are generally used as a discrete reinforcement in the substitution of steel fibers for improving certain properties of cementitious materials.The aim of this paper is to investigate the effect of fibers' content and dimensions on the fresh and mechanical properties of mortar.For this purpose fibers obtained from the previously consumed water PET bottles with four various percentages of 0, 0.25%, 0.5%, and 0.75% were incorporated in mortar mixtures.In addition, the fibers had 3 different dimensions of 2×10 mm, 2×20 mm, and 5×20 mm.Therefore, the width, length, and content of PET fibers were selected as the experimental variables.The fresh properties such as workability and fresh density were measured along with mechanical properties (compressive, flexural, and splitting strengths).The results indicate that both workability and fresh density of mortar mixtures have considerably decreased with the incorporation of PET fibers.While this reduction was more significant for longer fibers than shorter ones and thinner fibers compared to the wider ones.Moreover, the mechanical properties were improved with the incorporation of fibers compared to the control specimens and this improvement was more remarkable for longer fibers.The samples containing PET fibers showed more ductile behaviors in comparison to the brittle performances of reference samples.