Porosity and strength of self-compacting concrete incorporating waste plastic as: Fibers and fine aggregate

This study aims to investigate the impact of incorporating recycled Polyethylene Terephthalate plastic on porosity and compressive strength of the self-compacting concrete and the relation between them. This is by using the Polyethylene Terephthalate as fibers and as fine aggregate replacement. Five proportions were used for each type of Polyethylene Terephthalate (0.25, 0.5, 0.75, 1.0, and 1.25) % as volume fractions for fiber addition of the mix total volume and (2, 4, 6, 8, and 10) % by volume as replacements of sand with fine Polyethylene Terephthalate. All mixes were compared with a reference self-compacting concrete mix that has no Polyethylene Terephthalate. The porosity showed a notable increase for all proportions of the two types of Polyethylene Terephthalate but the self-compacting concrete mixes containing fine Polyethylene Terephthalate showed higher values than mixes with the fiber-Polyethylene Terephthalate. As for the 28-day compressive strength, it showed a decrease in all mixes compared with the reference mix. As for the same type of Polyethylene Terephthalate there was no constant changing among the mixes whether they all rise or fall in values. The same is for porosity. The result obtained from correlation coefficient revealed that there is an inversely weak relation between porosity and compressive strength.