Impact of treated palm oil fuel ash inclusion on hardened properties of self-compacting concrete

This study investigates the effects of incorporating treated palm oil fuel ash (POFA) as a partial cement replacement in self-compacting concrete (SCC) at replacement levels of 0%, 20%, 40%, and 60%. The hardened properties evaluated include compressive strength, initial surface absorption (ISAT), porosity, water absorption, gas permeability, water permeability, chloride ion permeability and chloride ion migration (RCPT and RCMT). After 180 days, the POFA-SCC40 mixture (40% substitution level) had the highest compressive strength of 85.11 MPa, which was stronger than the control mixture (OPC-SCC), which had a strength of 62.6 MPa. POFA-SCC60 mixture exhibited superior impermeability properties, with the lowest ISAT value recorded of 0.017 ml/m2/s, porosity of 4.09%, and water absorption of 0.95%. While the control mixture recorded an ISAT value of 0.031 ml/m2/s, porosity of 5.15%, and water absorption of 1.6%. The POFA-SCC60 mixture significantly reduced the gas and water permeability coefficients, indicating increased durability. In the POFA-SCC60 mixture, chloride ions had a hard time getting through. It had the lowest total charge passed (45 Coulombs) and no chloride penetration depth at 180 days, compared to the reference blend's (2545 Coulombs). These results show that adding up to 60% POFA to SCC makes it stronger and more durable. This approach is practical and sustainable for the construction industry, resulting in high-performance green SCC.