Structured mixture proportioning for oil palm kernel shell concrete

Abstract

Proportioning based on the principles of absolute volume method was used to obtain specific properties of lightweight concrete of oil palm kernel shells (OPKS). The sand content was determined depending on the cement content and OPKS/sand ratio. The trapped air volume of 5% and Water/cement ratio of 0.45 were fixed according to previous authors' works. The cement content ranged from 400 to 550 kg/m3, and the OPKS/sand ratio ranged from 0.4 to 0.75. The mixture proportions of C:S:OPKS in weight of 1:1.60:0.96 and 1:1.53:0.99 with cement content of 450 kg/m3 resulted in values for workability (≥20 mm), density (1800 ≤ d ≤ 1900 kg m3) and cylindrical compressive strength (≥ 15 MPa), which are recommended by ACI and British Code for structural lightweight concrete. This study, as part of efforts toward a structured method of proportioning of eco-friendly composite, demonstrates the possibility of linking mix proportions to properties of lightweight OPKS concrete.