Exploring the Use of Palm Kernel Shell and Palm Fibre As Sustainable Aggregates in Concrete

Palm kernel shells and palm fibres are leftover materials from the palm oil industry. However, they are not fully utilized and encounter disposal issues, particularly in Malaysia where they are produced in large quantities. This research aims to enhance sustainability and reduce palm waste disposal in Malaysia by exploring the potential of substituting palm waste for conventional aggregates. Six experiments were carried out to assess both the physical properties (including density, UPV, and water absorption) and mechanical properties (such as compressive strength, flexural tensile strength, and splitting tensile strength). The results indicate that a 35% palm kernel shell substitution is optimal, and it was able to produce a concrete specimen of 18 MPa cube strength, approximately 40% lower than the control specimen's 30 MPa. Despite this reduction, the strength is adequate for structures such as driveways, footings, and footpaths. The flexural and splitting tensile strength were the highest, at 4.99 MPa and 2.36 MPa, respectively. This batch also exhibited the best physical properties with a density of 2149 kg/m3, UPV of 3828 km/s, and water absorption of 9.31%. Additionally, the research also concludes that the addition of palm fibre in concrete tends to increase tensile strength by about 6%.