Limestone derived from eggshell powder as replacement in Portland cement mortar
In recent years, a general trend exists to reduce usage of natural resources and re-use waste materials.
Eggshell based limestone mortars had lower properties
The researchers developed a processing method to produce large quantities of eggshells. Limestone amounts of 0%, 5%, 10%, 15% and 20% by weight were added as Portland cement replacements. Chemical composition, elevated temperature degradation and eggshell particle morphology were investigated. Compression and flexural strength measurements were carried out on mortar specimens. The results showed eggshells contain mostly calcite with small amounts of organic membrane and matrix. The powdered eggshell particles appeared to have an irregular morphology due to the grinding process utilised. The strength of the mortars were affected by the addition of various limestone materials. In conclusion, white and brown eggshells derived limestone powder were found to have inferior properties compared to natural conventional limestone even with 5 wt.% Portland cement replacements.
The study is published in: Construction and Building Materials, Volume 95, 1 October 2015, Pages 1-9.