The possibility of using plastic instead of cement in construction

Abstract

Now more than ever, researchers are devoting their time and effort into finding innovative solutions for solid waste management. This thesis focuses on plastic wastes, one of the most common types of solid wastes. The goal of this study is to explore opportunities in using recycled plastic as a substitute to cement to form bricks and use them to make foundations, bridges, walkways and barriers more stable in the future in this way. Interest has been shown on how plastic could be utilized in construction as substitute to cement. This study aims at investigating the usage of recycled plastic wastes as a constituent instead of cementitious composites in concrete. The consequences of this product on the mechanical and physical properties of concrete were investigated. Polyethylene terephthalate (PET) and high-density polyethylene (HDPE) are the two main types of plastic that will be considered. The preparation of eco-bricks includes the cutting, melting, and mixing of plastic waste with sand, then molding of the materials. A group of plastic molds containing PET and HDPE in addition to river sand with different proportions of plastic and sand tested. The aim was to detect optimal composition and proportion of plastic and sand in order to achieve the desired properties. Results have shown that mixture containing equal proportions of sand and PET has the highest shrinkage, water absorption, flexural strength, compressive strength and splitting tensile strength. Moreover, mixture containing HDPE could not be tested in different sand/HDPE proportions due to the toxic emission generated from melted HDPE. As a conclusion, plastic proved to be a possible alternative of cement in appropriate proportions. The new in this study, that the mixture is composed only of sand and plastic, tested in different proportions and for various tests.