The Role of Oil Palm Shell Variant Specification on Compressive Strength of Ops Concrete Mixes

Oil palm shells (OPS), a major byproduct of the oil palm industry, pose environmental challenges due to their excessive availability and disposal issues. Over 40 years of research has been explored using oil palm shells (OPS) as coarse aggregates in structural lightweight concrete (SLWC). This study analyzed 138 mix designs from prior research, comparing their 28-day compressive strengths. A meta-analysis using Excel and Response Surface Methodology (RSM) revealed that the primary cause of strength variance, in spite of similar mix designs, is the type of OPS variant used, particularly differences between Dura and Tenera OPS variants. Tenera OPS, in particular, has a significantly lower compressive strength than Dura OPS produced with a similar mix design, highlighting the importance of specifying OPS varieties in research, which has been identified as a major omission in OPS concrete research.