Evaluation of the Pozzolanic Activity of Palm Bunch Ash from Rivers State Oil Palm Processors

This study evaluates the pozzolanic activity of palm bunch ash (PBA) generated from oil palm processing operations in Rivers State, South South Nigeria, as a potential supplementary cementitious material. Oil palm processing is a major agro-industrial activity in the South South zone, generating large quantities of empty fruit bunch residues that are typically incinerated, producing ash with potentially reactive siliceous and aluminous phases. Palm bunch ash samples are collected from three processing facilities in Emohua and Ikwerre Local Government Areas, calcined under controlled conditions at 600 and 700 degrees Celsius, and characterised by XRF, XRD, and BET surface area analysis. Pozzolanicity is assessed by the Frattini test and strength activity index. Cement pastes and mortars incorporating PBA at 0, 5, 10, 15, and 20 percent replacement levels are prepared and tested for compressive strength at 7, 28, and 56 days. Heat of hydration and chloride permeability are also measured. Results indicate that PBA calcined at 600 degrees Celsius exhibits higher amorphous silica content and passes the Frattini test, confirming pozzolanic reactivity. Strength activity index at 28 days exceeds 75 percent at 5 and 10 percent PBA replacement. Chloride permeability decreases with increasing PBA content, suggesting improved durability. Keywords: palm bunch ash, pozzolanic activity, supplementary cementitious material, Rivers State, durability.