Mechanical Properties of Low Densities Lightweight Foamed Concrete Strengthen with Raw Empty Fruit Bunch Fibre

Lightweight foamed concrete (LFC) is well known as a low-density concrete with a wide range of applications. LFC is good under compression but very poor in bending and tensile stresses, as it produces multiple microcracks and cannot withstand the additional stress induced by applied forces without supplementary reinforcing components especially in low densities LFC. Hence this study experimentally examined the effectiveness of the inclusion of oil palm empty fruit bunch (EFB) fibre in low densities lightweight foamed concrete (LFC) to enhance its mechanical properties. LFC specimens were reinforced with EFB fibre at volume fractions of 0.15%, 0.30%, 0.45%, and 0.60%. Three low densities LFC had been considered in this study namely 550 kg/m3, 750 kg/m3 and 950 kg/m3 with a constant cement-to-sand ratio of 1:1.5, and cement-to-water ratio of 0.4. The parameters assessed were compressive strength, bending strength and splitting tensile strength. The results revealed that the inclusion of 0.45% of EFB fibre in LFC helps to give the best results for the compressive, bending and splitting tensile strengths. EFB fibre acts as fillers bridging the gaps and microcracks within the LFC, resulting in the high strengths. The EFB fibre helped to avoid the promulgation of cracks in the plastic state in the cement matrix when the load was applied. Though, beyond the optimum level of EFB fibre addition, agglomeration, and the non-uniform dispersion of fibres was observed, which results in the lowered performance of the low densities LFC.