Utilization of Ethylene-Vinyl Acetate (EVA) Waste from Footwear Industry as Partial Replacement of Aggregates for Concrete Roof Tile

Abstract

Scraps of Ethylene-Vinyl Acetate (EVA) foams from cutting out shoe soles are a waste produced by the footwear industry, and the recycling of these thermosetting materials is quite expensive and requires distinct procedures. Hence, an upcycling route to turn such waste into valuable material, such as utilizing it as a partial aggregate replacement in the production of concrete roof tile, was explored. This paper aims to investigate the effects of EVA on the bulk density, water absorption, thermal properties, water permeability, and transverse breaking strength of the concrete roof tile. The weight percentages of replaced natural aggregates in the concrete roof tile mixture are 5%, 7.5%, and 10%. The concrete roof tile with EVA aggregates demonstrated a lighter weight but higher water absorption. Also, its thermal conductivity presents promising results as it lessens the heat transfer compared to conventional concrete roof tiles. Moreover, the incorporation of EVA also positively affects the concrete roof tile's water permeability as it can hold the water longer than those without EVA. Finally, the transverse breaking strength of the concrete roof tiles with EVA contents resulted little or no difference compared to the conventional concrete roof tile.