Characterization and Strength Activity Index of Eggshell Powder and Silica Fume as Partial Cement Replacement

Abstract

The rapid construction activity in Malaysia has increased the demand of concrete. One of the key ingredients in concrete is cement. The production of cement emits carbon dioxide (CO2) which is harmful to the environment. To overcome this issue, waste materials such as eggshell powder (ESP) and silica fume (SF) are incorporated in concrete as partial replacement to cement. In this research, the characterization and strength activity index (SAI) of ESP and SF as partial cement replacement were performed. The results showed that only SF was classified as pozzolanic materials of Class F, as specified in ASTM C618. Meanwhile, ESP had higher loss on ignition (LOI) than SF, hence contained higher amount of unburnt carbon. SF mortar had the highest SAI and compressive strength due to the small size of SF particles. Although ESP mortar fulfilled the minimum requirement of SAI as specified in ASTM C618, its compressive strength was lower than the Ordinary Portland Cement (OPC) mortar because the LOI content of ESP was more than 20%.