Influence of polyethylene terephthalate (PET) and crumb rubber on the properties of concrete / Norhana Abdul Rahman

Plastics and rubbers are user friendly but not eco-friendly as they are non-biodegradable. Generally, plastics and rubbers disposed by landfill treatment. However, this practice of disposing is becoming unacceptable because of the rapid depletion of available sites due to the volume of wastes increasing at a fast rate. To address this problems encountered, polyethylene terephthalate (PET) and crumb rubber (CR) have been suggested to be used as partial replacement to fine aggregate (FA) in concrete. Most of the studies conducted by previous researchers show that there is a feasibility of using these waste materials in concrete. Thus, recycling wastes PET and CR as FA in concrete could be one of the best solutions for disposing of it, given its economic and ecological advantages. Therefore, this research was conducted to enhance better understanding of the possibility of using PET and CR as FA replacement in concrete. Besides, the study on the combination of PET and CR in construction industry is still lacking. Thus, the aim of this research is to determine the influence of PET and CR on the properties of PET, rubberised and PET-rubberised concretes. The FA was replaced by PET (5%, 10%, 15%, 20%, 25% and 30%) and CR (10%, 20% and 30%) by weight and tested for 7, 28, 60 and 90 days of curing. As an improvement for rubberised and PET-rubberised concretes, the treatment using NaOH to the CR prior to mixing was applied to increase the hydrophilicity of the rubber particle surface.