Mechanical and thermophysical characterization of gypsum composites reinforced by different wastes for green building applications

Abstract

This paper presents three types of gypsum reinforced with different waste materials, such as paper, polystyrene, and polyester. Several investigations were performed through a set of multiphysics tests, including mechanical (flexural and compression strengths), physical (density and water absorption coefficient), microscopic (SEM), thermophysical, and ultrasonic measurement techniques. The results revealed that the gypsum elaborated with the use of the three wastes generates a good balance for the optimization of mechanical and physical properties, with a good interaction between residues and the gypsum matrix. In comparison with the neat gypsum sample, the results show a clear increase in flexural strength (up to 5.75 MPa) and water absorption coefficient (up to 96%). The drop in density to 0.718 g/cm3 makes this new material both light and insulating, with a reduction of thermal conductivity and sound propagation velocity of 40.5% and 34%, respectively. This paper provides a solution to recycle waste materials and transform them into useful interior insulation materials for building applications.