Reprocessing Post-Consumer Expanded Polystyrene: Mechanical and Thermal Properties of Lightweight Concrete Made With Postconsumer Expanded Polystyrene

Abstract

Expanded polystyrene foams (EPS) are used as packaging materials and are often discarded by consumers after the goods are unpacked (WEPS). Most recycling centers do not accept them because their extremely low weight makes them uneconomic to transport. In the research described here, WEPS was collected from shipping containers and crushed in a blender into 2-4 mm spherical shapes that were used as a replacement for aggregates to make lightweight concretes (LWC) to build lightweight facilities. Eight types of concrete samples were prepared, with the WEPS replacing the natural aggregate at the levels of 0 to 85 percent by volume to study the effects of the WEPS on the properties of the LWC. The densities of the LWCs were less than that of those found from natural aggregate (NAG), as was expected (900–1700 kg/m³). The heat conductivity of the LWC samples was smaller than that of NAG when the composition of WEPS was below 50%. The 28-day compressive strengths of the LWC ranged from 11 MPa to 90 MPa, which satisfies the strength requirement of semi-structural LWC recommended by ASTM to be higher than 17 MPa.

Keywords:

• compression
• expanded polystyrene
• heat transfer
• lightweight concrete

Acknowledgements

We acknowledge the support of the U.S. Department of Agriculture, National Institute of Food and Agriculture, Evans-Allen project number SCX-311-29-21. Any opinions, findings, conclusions, or recommendations expressed in this report are those of the authors and do not necessarily reflect those of the Funding Agency. Also, we express our gratitude to Dr. S. Ihekweazu, Dr. J. Salley and, Dr. L. Whitesides, and their teams of coworkers at SCSU, for constant encouragement and support.