Compressive behavior of Habesha eggshell particulate reinforced epoxy composites

Environmental pollution has become one of the major challenges to overcome in recent decades. Disposing waste materials has caused great concern by creating a landfill burden and increased environmental pollution. Utilizing or recycling wastes is one of the approaches considered that could bring positive environmental and economic benefits. Eggshells are among the understated waste materials that have great potential to impact the material world. In the present work, Habesha eggshells native to Ethiopia are utilized to prepare epoxy based composites. Five types of composites by varying the Habesha eggshell content (0, 2.5, 5, 7.5, and 10 vol%) are investigated. Physical characterization in terms of density and void content estimations, and eggshell particle size analysis are carried out. Mechanical characterization in terms of normal and quasi-static compression tests are performed. Results infer the density of eggshell particles to increase with increasing eggshell content, while quasi-static compression tests infer that modulus and strength of eggshell/epoxy composites are sensitive to variations in the strain rate. However, irrespective of the strain rates, all the eggshell/epoxy composites depict higher modulus as compared with neat epoxy specimens. At 1.43, 0.1, and 0.001 strain rates, increase in modulus of composites are in the range of 17%-57%, 3%-107%, 30%-114%, respectively. Further, compressive yield strength of all the Habesha eggshell/epoxy composites is low compared with epoxy specimens for all the strain rates investigated. Scanning electron micrographs of test specimens for different loading conditions reveal reinforcing egg shell particles assists in absorbing the loading effectively.

Automated summary

Environmental pollution is a major challenge that needs to be addressed, and utilizing or recycling wastes can bring positive environmental and economic benefits. In this study, epoxy based composites were prepared using Habesha eggshells from Ethiopia, and their physical and mechanical properties were characterized. The results showed that increasing the eggshell content led to higher density of the composites, and the modulus and strength were sensitive to variations in the strain rate.