Development of lightweight structural brick with polyurethane and composite fibers to increase mechanical performance

Composite materials have emerged as pivotal components in sustainable engineering, offering significant potential to enhance energy efficiency. This study explores the development of polyurethane (PU) matrix composites as lightweight structural elements designed to replace conventional brick and reinforced concrete systems. The primary objective is to reduce the dead load of buildings, thereby decreasing the seismic demand on structural members during earthquakes. To achieve this, a systematic experimental approach utilizing the Taguchi design methodology was employed to investigate the effects of glass, carbon, and basalt fiber reinforcements on the mechanical strength of the PU matrix. The experimental findings highlighted that fiber selection is a critical determinant of mechanical behavior. Composites reinforced with glass and basalt fibers exhibited superior compressive and flexural performance compared to carbon fiber variants. In contrast, carbon fiber-reinforced composites displayed lower strength, attributed to challenges in maintaining structural integrity and issues with fiber distribution during casting. Further statistical analyses using ANOVA and S/N ratios suggest that fiber dimension exhibits the highest relative contribution among the investigated parameters influencing material properties, with glass fiber reinforcement showing comparatively favorable mechanical performance. To validate the experimental results, analytical investigations were conducted via Finite Element Modeling (FEM), which confirmed that additive clusters significantly increase rigidity and reduce displacement in the PU matrices. As a result of this comprehensive study, a fiber-reinforced carrier material inspired by adobe was developed. This innovative, low-weight material offers a viable solution for energy-efficient structural applications, combining insulation properties with the mechanical capacity required for earthquake-resistant design.