Recycled Aggregates Based on Plastic Waste from WEEE

Abstract

Waste from Electrical and Electronic Equipment (WEEE), such as small/big home appliances, TVs, computers and smartphones, has turnedinto a significant and growing pollution issue. WEEE is a complex mixture of materials and components, and around 25% in weight is plastic. The plastic components of WEEE (WEEEP) contains about 30-35% w/w of acrylonitrile butadiene styrene, 20-25% w/w of high impactpolystyrene, 20-30% w/w of polypropylene and 10% w/w of polycarbonate. The presence of hazardous metals, metalloids and flame retardants has a negative impact on the recycling of WEEEP, despite their potential reuse. However, since the volume of this waste is continuously growing, its toxicity produces a rising negative impact on the environment and, in consequence, on human health. Hence, new technologies are required to revalue these wastes, but with no toxic consequences. Numerous examples can be found from the use of WEEEP as an aggregate to cement mixtures, but without considering its potential polluting power. In order to diminish WEEE pollution and to bring a effective response to turn this waste into a suitable and unharmful material, a novel stabilization strategy has been developed, consisting on the manufacture of a recycled plastic aggregate (RPA) for construction industry. The aggregate is based on the Core-Shell concept, which implies the use of a grinded WEEEP (core) with several layers of a mixture of cement and activated charcoal (shell).The technology developed is simple, robust, and requires low-cost equip-ment and basic infrastructure investment.The Core-Shell strategy produces the stabilization of the hazardouscompounds, mainly BFRs, that have not been stabilized in the cementmatrix. The techanical properties, together with the physical characteristic of the RPA obtained in this research work, position it as an excellent alternative to be used aggregate in place of sand in cement mortar or in the manufacture of building component such as bricks, isolating plates or precast concrete building components.