Mechanical and Physical Characteristics of Oil Palm Empty Fruit Bunch as Fine Aggregate Replacement in Ordinary Portland Cement Mortar Composites

Palm oil empty fruit bunch (OEB) is the largest source of waste in the production of crude palm oil. Utilizing this waste in various applications can help reduce its volume and mitigate adverse environmental effects. In this study, fibers from OEB without any chemical treatment are introduced into Ordinary Portland Cement (OPC)-based mortar to partially replace fine aggregates, aiming to reduce the mortar's density. The goal of this experimental study is to observe the mechanical and physical performance of the samples according to the effect of the addition of OEB. The composite samples were made by replacing 1%, 2%, and 3% of the weight of quartz sand as the fine aggregate with OEB (fine and coarse). The hardened composites were further tested to determine their compressive strength, and it was found that the replacement of sand with OEB led to a decrease in compressive strength and flowability while alleviating the mortar's density and affecting the setting time. The decrease in compressive strength was attributed to cavities present in the samples. Flexural tests and 28-day drying shrinkage measurements were carried out on the samples with 1% replacement of sand with OEB. The experiments showed that OEB fibers increased the flexural strength, functioned as a crack barrier, and reduced drying shrinkage.