Evaluation of polyethylene terephthalate in concrete

In recent years, advances in concrete technology have led to the invention of new forms of sustainable concrete. To prevent contamination of land and water supplies, daily use of the massive number of plastic polymers normally followed by a significant volume of waste needs to be controlled. According to statistics provided by the Malaysian Department of National Solid Waste Management, plastic waste is the second largest of the total solid waste produced in Malaysia and one of the most successful methods of reducing plastic waste is to reuse plastic waste in concrete. Polyethylene Terephthalate (PET) has good properties that can innovate and improve concrete properties. The goals of this research are to determine the properties of PET fibre concrete due to percentages (0.5%, 1.0%, 1.5% and 2.0%) for fresh, hardened, and non-destructive testing (NDT) methods. Concrete samples were tested using NDT such as acoustic emission test, thermal conductivity test and ultrasonic pulse velocity test. The fibres were simply cut from PET plastic bottles. The length and width of recycled PET fibres were fixed at 25 mm and 5 mm, respectively. The specimens were tested on day 7 and day 28 after the concrete was mixed. Tests were performed a slump test, a compressive strength test, splitting strength test and a flexural strength test to assess the mechanical properties and the optimum percentage of PET fibres. From the data analysis, the highest compressive strength of 49.80 MPa was obtained by a concrete specimen containing 1.0% PET at the age of 28 days. The cylinder specimen contained 0.5% PET achieved the highest splitting tensile strength at 3.95 MPa. The presence of 1.5% PET for specimens aged for 28 days had a signal strength of 9.5 × 108 pVs. Meanwhile, the maximum readings of absolute energy were obtained by specimens containing 1.5% of PET at 11.5 × 108 aJ. In addition, the highest amplitude value gained from this study is 99dB. From the UPV test, the highest velocity value is 4168m/s. The thermal conductivity value for specimens containing 1.0% of PET is 0.56 W/mK. From the RA value analysis, it can be concluded that the concrete specimen failed through tensile cracking. Meanwhile, the highest signal strength and absolute energy prove that the specimens have better resistance towards cracking. Moreover, the RA value analysis is appropriate for concrete crack classification. Therefore, the AE technique is found to be suitable for crack evaluation and monitoring methods

Sound absorption for concrete containing polyethylene terephthalate waste

Plastic solid waste generation increases every year with the current consumption habit prevalent in society nowadays. The improper disposal of plastic has been a major concern to the environment as it is not easily degradable. The issue of environmental pollution caused by polyethene terephthalates (PET) has been extensively discussed and the best solution proposed is recycling. Fibre Concrete (FC) was a composite material resulting from the addition of fibres to ordinary concrete. The objective of this research was to determine the acoustic absorption coefficient of concrete containing 0%, 0.5%, 1.0%, 1.5%, 2.0% of PET fibre compared to normal concrete. In this study, straight and irregular recycled PET fibres were used. The fibres were simply cut from PET plastic bottles. The length and width of recycling PET fibre were fixed at 25 mm and 5 mm respectively. The chosen percentages were 0.5%, 1.0%, 1.5% and 2.0% of fiber. A water-cement ratio of 0.45 was acceptable for all ranges. The tests that were conduct include the slump test, compression test, and impedance tube test. The specimens were tested on day 7 and day 28 after the concrete is mixed. The end of this research results for the compressive strength of normal concrete after 28 days of curing was 48.2 MPa while concrete with 0.5% PET, 1.0 % PET, 1.5% PET and 2.0% PET recorded a compressive strength of 50.9 MPa, 49.8 MPa, 47.9 MPa and 46.6 MPa respectively. The result of the impedance test received at age 28 days was 0.13 for normal concrete and 0.16, 0.14, 0.16 MPa, and 0.14 for 0.5% PET, 1.0 % PET, 1.5% PET and 2.0% PET respectively. In conclusion, the aspect ratio of the fibres to the concrete must be correlated to avoid reducing durability. In conclusion, the addition of 0.5% PET recycled fibre into concrete showed the best value in terms of strength and 0.16 for the sound absorption coefficient