A review on application of oil palm shell as aggregate in concrete - Towards realising a pollution-free environment and sustainable concrete

Abstract

The considerations for using alternative materials as coarse aggregate in construction industry is driven by the needs to conserve natural resources, reduce the huge amount of greenhouse gas emission and environmental degradation related to conventional aggregate. Efforts to alleviate food insecurity has resulted in increased agricultural activities across the world. However, the processing of agricultural produce generates huge amount of residues as by-products the disposal of which is of great concern. Oil palm shell (OPS) which is a by-product from oil palm industry has shown potentials as an alternative to the conventional aggregate in concrete production. OPS is a suitable material for the production of structural lightweight aggregate concrete having better thermal insulation, reduced density of roughly 20 to 25% less than conventional aggregate concrete, and a 28-day compressive strength greater than 17 N/mm2. Previous studies on the properties of OPS, fresh and hardened properties of OPS concrete, as well as its eco-efficiency and environmental aspects are summarized in this paper. In addition, the various improvement techniques employed on OPS and OPS concrete that resulted in improved OPS concrete performance are also highlighted. With large quantities of OPS produced in tropical parts around the world, its total adoption as aggregate in these regions is still fairly limited. Long-term studies on mechanical strength, thermal and durability properties of OPS concrete are recommended to promote the usage of OPS as aggregate in actual structures.

Keywords

• Lightweight aggregate
• Mechanical properties
• Normal weight concrete
• Oil palm shell concrete
• Sustainability