Emerging Tenera oil palm shell concrete: Mix design and cost analyses

Abstract

The utilization of oil palm shell (OPS) in concrete dates back since four decades ago. While most research has only been done on the Dura-OPS as coarse aggregate in concrete, few research has been done on Tenera-OPS. The Tenera-OPS is obtained by a hybrid crossbreeding between Dura and Pisifera type fruits to obtain a thinner shell in the palm oil fruit to produce 30% more palm oil. Tenera-OPS has different physical properties compared to Dura-OPS, which could alter the mechanical behaviour of concrete. Therefore, this paper has studied mix designs of Tenera-OPS concrete (Tenera-OPSC) to investigate its physical characteristics, and compressive strength and has compared to those of Dura-OPSC from literature. It has been found that compressive strength of 20.24 MPa could only be produced with very high cement content of 1050 kg/m3. This study has shown that the compressive strength of Tenera-OPSC is reduced by 55 – 72% by using the most common acceptable mix design used for Dura-OPSC. It has been found that Tenera-OPS in concrete swells and shrinks during the hardening process which causes de-bonding between the Tenera-OPS and the cement matrix, which is believed to be the main reason for the lower compressive strength. A cost analysis was also done to compare the costs between Tenera-OPSC and normal weight concrete (NWC) of similar grade. The cost of Tenera-OPSC has been found to be 2% lower than that of NWC.