Lightweight Material Made with Gypsum and EPS Waste with Enhanced Mechanical Strength

Huge volumes of expanded polystyrene (EPS) waste are landfilled every year, increasing the damage that the environment is suffering. The production of a lightweight construction material made with gypsum and EPS waste is an alternative method to reduce EPS waste landfilling. However, this material has a very low mechanical strength, not meeting the minimum requirement for compressive strength. Therefore, the aim of this research work is to study the reinforcement of this lightweight material by incorporating different additives (latex, binding additive, plasticizers) and fibers (glass fiber and polypropylene fiber). Detailed consideration is given to the particle size of EPS waste; therefore, reinforced composites have been designed for fine EPS waste (1-2 mm) and coarse EPS waste (2-4 mm). The characteristics of these composites were defined and tested by fixing the consistency at a good workability and then studying their density, Shore C surface hardness, flexural and compressive strength, and their thermal conductivity. Results show that it is possible to create a lightweight material made with gypsum and EPS waste with enhanced mechanical properties, low density, and an outstanding thermal behavior. However, the use of coarse EPS waste has a negative effect on the Shore C surface hardness, especially with latex and fibers. (C) 2015 American Society of Civil Engineers.