The Effect of Untreated Dura-Palm Kernel Shells as Coarse Aggregate in Lightweight Pervious Concrete for Flood Mitigation

Abstract

This research aimed at ascertaining the performance of raw dura species of Palm Kernel Shells (PKS) in comparison to a different species of PKS (tenera) as a replacement for known aggregates for pervious lightweight concrete. Using limestones as the known aggregates, control pervious concrete was batched, and relevant tests were conducted. Major tests conducted on the composites concerned compressive, tensile, and flexural strength, as well as permeability, densities, and absorption. Logistic constraints on transporting the dura-PKS limited the quantity needed to ascertain the variety of replacements of the dura-PKS. With a 25% replacement known to be the most suitable ratio for related investigations, we adopted that ratio and compared to the extreme ratio of 100% dura-PKS. The tests revealed that a 100% replacement of known aggregates by the dura-PKS resulted in high porosity and permeability, although the resistances to compression, tension, and flexural loads read low for the same mixture. Instead, pervious concrete 25% of dura-PKS replacement yielded optimum water permeability rate and flexural and compressive stresses. However, the flakiness index recorded for the dura-PKS was almost half that of the tenera species and was not reflected in the mechanical properties as the results gave relatively lower strengths. The results in the case of the dura species do not differ significantly compared to the tenera-PKS in terms of strength and permeability.