Influence of Oil Palm Shell (OPS) on the Compaction Behavior and Strength Improvement of Soil-OPS Composites: A Pilot Study

Abstract

In construction industry, state-of-the-art experimental trials such as plastic road by Scottish and rubber road in Malaysia have shown potential value in the utilization of locally available wastes in engineering projects. Malaysia, the second largest global producers of palm oil and related products, estimates millions of tons of biomass by-product annually. Oil Palm Shell (OPS) is one amongst the biomass thus produced. OPS is well noted in literatures for its low specific gravity and better strength/stiffness, though not in absolute comparison to aggregates. Thus, an eco-composite with OPS supplementing conventional sub-base material hypothetically is a promising alternative, facilitating productive utilization of OPS – an agricultural waste, reducing the self-weight of the sub-base, and soil reinforcement leading to improved strength. The main aim of this paper is to study the influence of OPS content on the compaction behavior and strength improvement of soil-OPS composites for its application as sub-base material in rural roads. Basic properties of the OPS samples and three soil samples locally procured – kaolin, medium sand and clayey sand, were evaluated in laboratory. The performance of soil-OPS composite in terms of their compaction and California bearing ratios is evaluated and discussed in this paper. In conclusion, the OPS was observed to have significant influence on the compaction characteristics and strength (CBR). In brief, the porous surface texture of OPS is most likely the key parameter controlling the compaction parameters, while contributions from the tensile strength of individual OPS samples potentially has a significant influence on the strength (CBR) improvements observed in this pilot study.