Bond behaviour of oil palm broom fibres in concrete for eco-friendly construction

Global awareness of climate change and sustainability has attracted research into the use of natural materials in construction. Recent studies on the ribs of the leaflets of the oil palm tree (known as oil palm broom fibre (OPBF)) have reported impressive physico-mechanical properties. However, information on their bond behaviour with cementitious matrices is presently lacking. This study investigated the bond strength of single and combined OPBF in concrete through direct pull-out tests. Maximum bond strengths of 1.16, 0.95 and 0.82 MPa were recorded at 28, 56 and 112 days, respectively. The influences of the age of the sample and the diameter of OPBF tendons on the bond strength were assessed. Images obtained from scanning electron microscopy reveal embrittlement of fibre surfaces by cement matrix. Finite-element modelling of the pull-out behaviour was also carried out using Abaqus software. The potential use of OPBF combined in the form of tendons as longitudinal reinforcement in concrete for lightly loaded structural elements is environmentally friendly and can reduce construction costs.