Strength Characteristics of Recycled Polyethylene Fibre Reinforced Concrete

This paper reports on the compressive strength and flexural tensile behavior of recycled polyethylene fibre reinforced concrete. Twelve concrete cubes of dimension 150 mm ×150 mm × 150 mm containing 0%, 0.25%, 0.50% and 1.0% of polyethylene fibres were cast and tested per BS 1881-part 116: 1983 to determine the compressive strength. Twelve concrete prisms measuring 100 mm×100 mm×300 mm containing 0%, 0.25%, 0.50% and 1.0% of polyethylene fibres were also cast and tested under a center-point loading system using an Avery Denison universal testing machine per the American Society for Testing and Materials, ASTM C78-2009 to investigate the flexural behavior of the polyethylene fibre concrete. Results of the tests showed that, the compressive strength fell from an average of 33.07 N/mm2 for the plain concrete specimen to an average of 17.74 N/mm2 for the 1.0% fibre concrete specimen. The drop in average compressive strength is 22% for the 0.25% fibre concrete, 36% for the 0.5% fibre concrete, and 46% for the 1.0% fibre concrete specimen. These drops in compressive strength of the polyethylene fibre concrete are quite significant compared to the plain concrete. The modulus of rupture which is an indication of the flexural tensile strength of the concrete however increased from 6.56 N/mm2 for the plain concrete to 8.32 N/mm2 for the 1.0% fibre concrete. The percentage increase is 3% for the 0.25% fibre concrete, 14% for the 0.5% fibre concrete, and 27% for the 1.0% fibre concrete specimen. The polyethylene fibres therefore have a generally positive effect on the flexural strength of concrete.