Effect of Aspect Ratio of Recycled Plastic Strips on Mechanical ‎Behavior of Concrete at Different Ages.‎

Abstract

Concrete is one of the most important structural materials used in construction. The development of life has led to the appearance of a lot of waste, which affects and threatens the environment, such as plastic and household organic waste, etc. Recently, modern methods have been found to dispose of waste by recycling it using a new approach, which is green production. The reference concrete used in this research paper has a compressive strength of 37.14 MPa. Plastic water bottles, also chemically known as polyethylene terephthalate, were transformed into rectangular strips with a width of 2 mm, a length of 20 mm, and 30 mm. Thus, the aspect ratios 10 and 15.  The percentages of fiber strips were 1, 2, and 3% of concrete weight for each aspect ratio. The present research examined the behavior of concrete behavior after adding plastic waste as fibers at aspect ratios of 10 and 15 at rates of 1, 2, and 3% by weight of concrete.  Additionally, ninety-eight specimens were examined. Cubes (150 × 150 × 150 mm) were examined at ages 7, 14, 28, and 56 days, and 21 cylindrical specimens (150 × 300 mm) were examined at 28 days of age. Moreover, the workability of the fresh mixture was studied along with strength, tensile strength, ultrasonic pulse velocity, absorption and weight loss of hardened concrete. In this study, the results showed that the slump decreased with an increase in the fiber percentage, approximately 30 and 40 mm, respectively. The compressive strength was better at an aspect ratio of 15 compared to 10.  Furthermore, the tensile strength of all ratios increased (13, 10.4, and 5.5%) at an aspect ratio of 15, which also reduced absorbability.  The results showed a gradual but slight weight loss. In general, the result was better at an aspect ratio of 15.