Utilizing waste plastic polypropylene and polyethylene terephthalate as alternative aggregates to produce lightweight concrete: A review

Abstract

This research was conducted to study the effect of adding waste plastic fibers (WPFs) on the behavior of reinforced concrete (RC) beams. Fifteen simply supported RC beams with a cross section of (100 * 150) mm and a clear span of (1100) mm was tested under two-point loads until failure. Three beams of the total samples were made from the reference mix, and the twelve beams remaining were made from concrete mixes containing WPFs with volumetric percentage ratios (Vf) varying from (0.5% to 2%) of the total volume. These beams were divided into three main groups according to the longitudinal steel reinforcement area ratio (Ꝭ ), and these ratios were approximately equal to (Ꝭmax , 0.75 Ꝭmax, Ꝭmin).Test results established that the adding of WPFs, in addition, to decreasing the danger of PET wastes on the environment, leads to increasing the maximum applied load causing ultimate failure, an increment in ductility index and transformation of the mode of failure of the tested beams into a more ductile one for all beams contains such kind of fibers. An attempt was carried out to develop some properties of self-compacted concrete (SCC) by adding waste plastic fibers (WPF) resulting from cutting beverage bottles. Many tests were conducted to investigate the effect of adding WPF on the fresh properties, whereas other tests were applied on that kind of concrete to study the effect of this type of waste on hardened properties. For this reason, different self- compacting concrete mixtures were designed at constant water-to-binder ratio of 0.35 and 490 kg/m3 of binder content. The class F fly ash was replaced with cement as 25% by weight. The eighth designated plastic fiber contents of 0%,0.25%,0.5%,0.75%,1%,1.25%,1.5%,1.75% and 2% by volume. The workability properties of self-compacting concrete mixtures were performed to slump flow diameter, T50 slump flow simultaneously, V-funnel flow at the same time, and L-box height ratio. The 7, 14 and 28-day compressive strengths of self-compacting concretes were also measured. Moreover, the 7, 14 and 28-day flexural strengths of concretes were also measured. The test results showed that the plastic fibers have adverse effect on the fresh properties of self-compacting concrete and improvement by hardened properties.