This study aims to examine the effect of varying the length of oil palm empty fruit bunch (EFB) fibers on the mechanical properties and macrostructure of Palmfiber Reinforced Concrete (PRC) as an alternative to Glassfiber Reinforced Concrete (GRC). EFB fibers were selected due to their abundance, eco-friendliness, and potential to enhance the mechanical properties of lightweight concrete. The methods employed include flexural testing and macrostructural observation using five fiber length variations (3 cm, 4 cm, 5 cm, 6 cm, and 7 cm). The results show that a fiber length of 5 cm produced the highest flexural stress of 11.78 kg/cm², while a length of 4 cm yielded the highest modulus of elasticity at 162.2 kg/cm². Macrostructural observations revealed good bonding between fibers and matrix in most specimens, although performance differences were observed due to fiber distribution and manual compaction processes. In conclusion, fiber length affects the mechanical performance of PRC, yet production process optimization is necessary to achieve more consistent results.
