Eco-friendly use of eggshell powder as a bio-filler and flux material to enhance technological properties of fired clay bricks

In this work, an experimental investigation on the use of eggshell powder from waste eggshells as an alternative source of bio-filler and flux to enhance the technological properties of fired clay bricks were carried out. Four different batch compositions were formed with eggshell powder as a bio-filler and flux replacing clay-soil up to 15 wt.%. The clay bricks were prepared by the casting method and were fired at 800, 900, and 1000 °C at the heating rate of 8 °C/min for 120 minutes. The raw materials and produced fired clay bricks were characterized by SEM/EDS, XRF, and XRD, respectively. Besides, technological properties of fired clay bricks (eg. water absorption, apparent porosity, bulk density, and compressive strength) were also determined. The results showed that adding 15 wt.% of eggshell powder as a bio-filler and flux yielded a compressive strength of 4.8 MPa, the bulk density of 2.1 g/cm, and a lower water absorption value of 11.1% at the firing temperature of 1000 °C. Consequently, the use of eggshell as a bio-filler and flux to enhance the technological properties of fired clay bricks is promising and can be considered as an effective alternative method to reduce environmental concerns caused by inappropriate discarding and landfill construction to dispose of eggshell waste.