Plastic waste as a concrete mix component

Abstract

In the last decades, several strategies have been employed to improve the characteristics of concrete in terms of mechanical strength, ductility, durability, lightness, workability, ability to prevent the oxidation of steel reinforcement, etc. In this study a new point of view is faced, that is the possibility to use concrete as a container of waste without worsening, or containing the worsening, of the properties mentioned before. In detail, it is investigated the possibility of recycling plastic waste in different forms, by using it as aggregate in the production of concrete. The exploitation of waste, or byproducts, as alternative aggregate in concrete, and in detail is not new and results in a reduction in the exploitation of scarce natural resources. Productive use of waste leads to a reduction in the landfilling of waste through the transformation of waste into a resource. Here, plastic is not properly considered as a resource while concrete is considered a resource to limit the introduction of plastic waste in the environment. The introduction of plastic waste in the concrete is not new [1-12] but in many cases, the waste is transformed before its use. Introducing not transformed plastic waste into ordinary concrete mixes is a challenge because, in connection with the characteristics of the plastic waste, the risk of a loss of performance is not so low. To prove the possibility of reaching this objective with an acceptable loss of performance, the mechanical characteristics of concrete mixed with additional alternative plastic aggregates classified as waste are investigated and discussed in this paper. The experimental program includes the inclusion of different types of plastic wastes (different refers to the chemical composition and to the shape of the plastic aggregate) in the concrete. Different mixes with different percentages of waste are investigated to identify possible fields of application. The experimental results indicate that the use of plastic waste is possible within significant percentage ranges.