Effect of plastics on concrete plain and structural properties

Abstract

Nowadays, Polyethylene Terephthalate (PET) is being consumed in huge amounts all around the world. However, little effort was made so far to recycle this material, considering the high cost of recycling process compared to the extraction of raw material. As such, researchers are regularly trying to find new possible ways for reusing PET in different trades. This research study is carried out to examine the performance of concrete that contains PET bottle waste. Those wastes are chosen because they are thrown away after single use and causes many pollution problems. The study is conducted using ten samples of reinforced concrete (RC) beams to examine the performance of the concrete in terms of mechanical properties. A total of ten samples of concrete mixtures were mixed specifically, normal concrete and concrete containing PET and some admixtures such as the styrene-butadiene rubber and steel fibers. In this study, the results show that the presence of PET could degrade the concrete strength and performance. Nevertheless, the content of PET is limited to a specific ratio to avoid the excessive effect on the concrete strength itself. The graphs present the effect of PET and admixtures on RC beams in addition to a comparison with normal concrete. The load capacity of RC beams increases with a certain percentage of PET. The maximum allowable load for shear is set at 10% of PET with 0.8% steel fibers which is higher by 44% comparing to control. To note that a higher value in this ratio causes the load capacity to decrease. Steel fibers can lower the cracking point and it can improve the flexural strength, ductility, and mechanical properties as well.