Abstract
The objective of this study is to manufacture a geopolymer by replacing part of the metakaolinite by calcined oil-contaminated
clay (OCC) and investigate its properties. The effects of the calcination temperature, the mix design of the alkali activator, and
the degree of calcined OCC replacement on the properties of the geopolymer were studied. Evaluation of pozzolanic activity and
compressive strength as well as micro structure observation by SEM and XRD were performed in this study. The results indicate
the best strength activity index (SAI) was obtained that when OCC was calcined at 850°C. The concentration of alkali activator
needed to manufacture the geopolymer decreased with increasing degrees of calcined OCC replacement. It was found that 25%
calcined OCC replacement could efficiently improve the early compressive strength of geopolymer specimens. However, with
more than 75% calcined OCC replacement, the late strength of the geopolymer specimens decreased. Microstructural observation
showed similar results in that the amount of silicon was not sufficient for polymerization and the chemical bonding was reduced
at greater degrees of calcined OCC replacement. As a result, the late compressive strength of geopolymer specimens was
insufficiently developed.