Analysis of co-fired clay and palm kernel shells as a cementitious material in Ghana

The treatment of clay through a calcination process at high temperatures have been theusual and a common means of producing clay pozzolan as a supplementary cementitiousmaterial. However incorporating waste biomass as a component material in clay is veryuncommon. This work analyzed the use of palm kernel shells as a component material inclay and were calcined at a high temperature of 800C. The palm kernel shells were used toreplace clay at 10%, 20% and 30% by weight. Strength activity index prescribed by ASTMC311 was used to determine the maximum mixture proportion between calcined clay andpalm kernel shells. The calcined clay and palm kernel shell mixtures that gave themaximum strength were subjected to an incremental replacement dosage of Portlandcement between 10% and 40% by weight. Test results indicated that the maximum strengthmixture proportion between clay and palm kernel shells was obtained at 20% replacementof clay. Moreover the maximum value that showed a better strength performance throughthe incremental replacement by the calcined material was also at 20% Portland cementreplacement. The study recommended the use of palm kernel shells to a limit of 20% clayreplacement. The is because at higher content of palm kernel shells in clay calcined at a hightemperature, more unreactive crystalline phases are formed that inhibit reactivity ofpozzolanic active phases. The use of 20 wt.% of palm kernel shells in clay to produce asupplementary cementitious material provides a sustainable means of waste disposal viaconstruction application.