Study of concrete properties using polyethylene terephthalate (pet) as aggregate

Abstract

In the ever demanding field of Civil Engineering, the materials used for structural applications have been considered a vital issue regarding the safety, durability and stability of the structures. Also the reduction of waste materials and substituting these with the regular materials in structural applications seem to be a viable option and a lot of researches are going on considering this issue. Keeping this in mind, the use and study of concrete properties using Polyethylene Terephthalate (PET) as aggregates has been adopted in this research. Since waste PET bottles are rising in an alarming rate and the reuse of these waste materials is highly demanding, a lot of researches have been taken into account considering the uses of PET in the structural and nonstructural applications as aggregates. This research basically focuses on using melted PET as a partial replacement of coarse and fine aggregates. For this purpose 36 cylinders are prepared by replacing 20%, 30%, 40% and 50% by volume of the coarse aggregates and 50% by volume of the fine aggregates. Also three water-cement ratios (i.e. 0.42, 0.48 and 0.57) are taken under consideration for achieving optimum workability in using PET as aggregates. Afterwards, the test results obtained are compared with the cylinder specimens consisting regular aggregates. Firstly it has been observed that the cylinder specimens with melted PET as coarse and fine aggregates show a decline in compressive strength compared to the concrete samples with regular aggregates whereas the density of the former is reduced, making the concrete samples lightweight compared to the latter one. Secondly the workability increases with the increment of water-cement ratio of the samples. Thirdly the samples consisting PET as fine aggregates ensure better compressive strength compared to the samples having PET as coarse aggregates with the same watercement ratio though the density of the latter reduces more than the former samples. Finally the compressive strength of the concrete samples reduces with the increment of the replacement percentage of the PET as coarse aggregates.