Worldwide, the construction industry has acknowledged the future demand for lightweight construction materials, with high workability, self-compacting, and environmentally friendly. Given this demand, recent innovative material namely foamed concrete (FC), has been found to reduce normal concrete’s weight potentially. However, while FC made with Ordinary Portland Cement has good compressive strength, other characteristics such as tension are relatively weak given the number of micro-cracks. Therefore, the study focused on the potential use of oil palm fibres in FC regarding their durability and mechanical properties. Notably, one of the major issues faced in the construction of reinforced FC is the corrosion of reinforcing steel which affects the behaviour and durability of concrete structures. Hence, in this study, oil palm fibres were added to improve strength and effectively reduce corrosion. Five types of fibre generated from oil palm waste were considered: oil palm trunk, oil palm frond, oil palm mesocarp and empty fruit bunch consisting of the stalk and spikelets. Specimens with a density of 1800 kg/m³ were prepared in which the weight fraction of the fibre content was kept constant at 0.45% for each mixture. Testing ages differed in testing and evaluating the parameters such as compressive strength, flexural strength, tensile strength, porosity, water absorption, drying shrinkage and ultrasonic pulse velocity. The results showed that the incorporation of oil palm fibre in FC helped reduce water absorption, porosity and shrinkage while enhancing the compressive, flexural and tensile strength of FC.

• ASTM International. (2014). ASTM C878 / C878M-14a: 2014. Standard test method for restrained expansion of shrinkage-compensating concrete. ASTM International

• ASTM International. (2016). ASTM C293 / C293M-16: 2016. Standard test method for flexural strength of concrete (using simple beam with center-point loading). ASTM International.

• ASTM International. (2017). ASTM C496 / C496M-17: 2017. Standard test method for splitting tensile strength of cylindrical concrete specimens. ASTM International.

• British Standard Institution. (1983). BS 1881-122: 1983. Testing concrete. Method for determination of water absorption. British Standards Institute.

• British Standard Institution. (1992). BS 882: 1992. Specification for aggregates from natural sources for concrete. British Standards Institute.

• British Standard Institution. (1996). BS 12: 1996. Specification for Portland cement. British Standards Institute.

• British Standard Institution. (2004). BS 12504-4: 2004. Testing concrete. Determination of ultrasonic pulse velocity. British Standards Institute.

• British Standard Institution. (2011). BS 12390-3: 2011. Testing hardened concrete. Compressive strength of test specimens. British Standards Institute.

• Elrahman, M. A., El Madawy, M. E., Chung, S. Y., Sikora, P., & Stephan, D. (2019). Preparation and characterization of ultra-lightweight foamed concrete incorporating lightweight aggregates. Applied Sciences, 9(7), 1-12. https://doi.org/10.3390/app9071447

• Ezerskiy, V., Kuznetsova, N. V., & Seleznev, A. D. (2018). Evaluation of the use of the CBPB production waste products for cement composites. Construction and Building Materials, 190(30), 1117-1123. https://doi.org/10.1016/j.conbuildmat.2018.09.148

• Ferreira, S. R., De Andrade, S. F., Lima, P. R. L., & Filho, R. D. T. (2017). Effect of hornification on the structure, tensile behavior and fiber matrix bond of sisal, jute and curaua´ fiber cement based composite systems. Construction and Building Materials, 139, 551-561. https://doi.org/10.1016/j.conbuildmat.2016.10.004

• Fu, Y., Wang, X., Wang, L., & Li, Y. (2020). Foam concrete: A state-of-the-art and state-of-the-art practice review. Advances in Materials Science and Engineering, 2020, Article 6153602. https://doi.org/10.1155/2020/6153602

• Hamad, A. J. (2014). Materials, production, properties and application of aerated lightweight concrete. International Journal of Materials Science and Engineering, 2(2), 152-157. https://doi.org/10.12720/ijmse.2.2.152-157

• Hasan, K. M. F., Horvath, P. G., & Alpar, T. (2020). Potential natural fiber polymeric nanobiocomposites: A review. Polymers, 12(5), Article 1072. https://doi.org/10.3390/polym12051072

• Hasan, K. M. F., Horvath, P. G., & Alpar, T. (2021). Lignocellulosic fiber cement compatibility: A state-of-the-art review. Journal of Natural Fibers, 1-26 https://doi.org/10.1080/15440478.2021.1875380

• Hospodarova, V., Singovszka, E., & Stevulova, N. (2018). Characterization of cellulosic fibers by FTIR spectroscopy for their further implementation to building materials. American Journal of Analytical Chemistry, 9(6), 303-310. https://doi.org/10.4236/ajac.2018.96023

• Jalal, M. D., Tanveer, A., Jagdeesh, K., & Ahmed, F. (2017). Foam concrete. International Journal of Civil Engineering Research, 8(1), 1-14.

• Jhatial, A. A., Inn, G. W., Mohamad, N., Alengaram, U. J., Mo, K. H., & Abdullah, R. (2017). Influence of polypropylene fibres on the tensile strength and thermal properties of various densities of foamed concrete. In IOP Conference Series: Materials Science and Engineering (Vol. 271, No. 1, p. 012058). IOP Publishing. https://doi.org/10.1088/1757-899X/271/1/012058

• Kamaruddin, S., Goh, W. I., Jhatial, A. A., & Lakhiar, M. T. (2018). Chemical and fresh state properties of foamed concrete incorporating palm oil fuel ash and eggshell ash as cement replacement. International Journal of Engineering & Technology, 7(4.30), 350-354. https://doi.org/10.14419/ijet.v7i4.30.22307

• Karade, S., & Aggarwal, L. (2011). Cement-bonded lignocellulosic composites for building applications. Metals Materials and Processes, 17(2), 129-140. https://10.1016/j.conbuildmat.2010.02.003

• Kim, Y., Jiong, H., Jae, L., & Heeyou, B. (2010). Mechanical properties of fiber reinforced lightweight concrete containing surfactant. Advances in Civil Engineering, 10, 1-9. https://doi.org/10.1155/2010/549642

• Kochova, K., Gauvin, F., Schollbach, K., & Brouwers, H. (2020). Using alternative waste coir fibres as a reinforcement in cement fibre composites. Construction and Building Materials, 231, Article 117121. https:// doi.org/10.1016/j.conbuildmat.2019.117121

• Li, Q., Ibrahim, L., Zhou, W., Zhang, M., Fernando, G. F., Wang, L., & Yuan, Z. (2020). Holistic solution to natural fiber deterioration in cement composite using hybrid treatments. Cellulose, 27(7), 981-989. https://doi.org/10.1007/s10570-019- 02813-2

• Lim, S. K., Tan, C. S., Lim, O. Y., & Lee, Y. L. (2013). Fresh and hardened properties of lightweight foamed concrete with palm oil fuel ash as filler. Construction and Building Materials, 46, 39-47. https://doi.org/10.1016/j.conbuildmat.2013.04.015

• Mahmud, S., Hasan, K. M. F., Jahid, M. A., Mohiuddin, K., Zhang, R., & Zhu, J. (2021). Comprehensive review on plant-fiber reinforced polymeric biocomposites. Journal of Materials Science, 56, 7231-7264. https://doi.org/10.1007/s10853-021-05774-9

• Mahzabin M. S., Hock, L. J., Hossain, M. S., & Kang, L. S. (2018). The influence of addition of treated kenaf fibre in the production and properties of fibre reinforced foamed composite. Construction and Building Materials, 178, 518-528. https://doi.org/10.1016/j.conbuildmat.2018.05.169

• Majid, A., Anthony, L., Hou, S., & Nawawi, C. (2012). Mechanical and dynamic properties of coconut fibre reinforced concrete. Construction and Building Materials, 30, 814-825. https://doi.org/10.1016/j.conbuildmat.2011.12.068

• Memon, I. A., Jhatial, A. A., Sohu, S., Lakhiar, M. T., & Hussain, Z. (2018). Influence of fibre length on the behaviour of polypropylene fibre reinforced cement concrete. Civil Engineering Journal, 4(9), 2124-2131. https://doi.org/10.28991/cej-03091144

• Mohammadhosseini, H., Awal, A. S. M. A., & Sam, A. R. M. (2016). Mechanical and thermal properties of prepacked aggregate concrete incorporating palm oil fuel ash. Sadhana, 41(10), 1235-1244. https://doi.org/10.1007/s12046-016-0549-9

• Momeen, M., Islam, U., Mo, K. H., & Alengaram, U. J. (2016). Durability properties of sustainable concrete containing high volume palm oil waste materials. Journal of Cleaner Production, 137, 167-177. https://doi.org/10.1016/j.jclepro.2016.07.061

• Moon, A. S., Varghese, V., & Waghmare, S. S. (2015). Foam concrete as a green building material. International Journal for Research in Emerging Science and Technology, 2(9), 25-32.

• Müller, H. S., Breiner, R., Moffatt, J. S., & Haist, M. (2014). Design and properties of sustainable concrete. Procedia Engineering, 95, 290-304. https://doi.org/10.1016/j.proeng.2014.12.189

• Munir, A., Abdullah, Huzaim, Sofyan, Irfandi, & Safwan. (2015). Utilization of palm oil fuel ash (POFA) in producing lightweight foamed concrete for non-structural building material. Procedia Engineering, 125, 739-746. https://doi.org/10.1016/j.proeng.2015.11.119

• Muthusamy, K., & Zamri, N. A. (2016). Mechanical properties of oil palm shell lightweight aggregate concrete containing palm oil fuel ash as partial cement replacement. KSCE Journal of Civil Engineering, 20(4), 1473-1481. https://doi.org/10.1007/s12205-015-1104-7

• Mydin, M. A. O., & Zamzani, N. (2018). Coconut fiber strengthen high performance concrete: Young’s modulus, ultrasonic pulse velocity and ductility properties. International Journal of Engineering & Technology, 7(2), 284-287. https://doi.org/10.14419/ijet.v7i2.23.11933

• Mydin, M. A. O., Musa, M., & Ghani, A. N. A. (2016a). Fiber glass strip laminates strengthened lightweight foamed concrete: Performance index, failure modes and microscopy analysis. In AIP Conference Proceedings (Vol. 2016, No. 1, p. 020111). AIP Publishing LLC. https://doi.org/10.1063/1.5055513

• Mydin, M. A. O., Noordin, N. M., Utaberta, N., Yunos, M. Y. M., & Segeranazan, S. (2016b). Physical properties of foamed concrete incorporating coconut fibre. Jurnal Teknologi, 78(5), 99-105. https://doi.org/10.11113/jt.v78.8250

• Onuaguluchi, O., & Banthia, N. (2016). Plant-based natural fibre reinforced cement composites: A review. Cement and Concrete Composite, 68, 96-108. https://doi.org/10.1016/j.cemconcomp.2016.02.014

• Ramamurthy, K., Nambiar, E. K. K., & Ranjani, G. I. S. (2009). A classification of studies on properties of foam concrete. Cement and Concrete Composites, 31(6), 388-396. https://doi.org/10.1016/j.cemconcomp.2009.04.006

• Sari, K. A. M., & Sani, A. R. M. (2017). Applications of foamed lightweight concrete. MATEC Web of Conferences, 97, 1-5. https://doi.org/10.1051/matecconf/20179701097

• Serri, E., Mydin, M. A. O., & Suleiman, M. Z. (2014). Thermal properties of oil palm shell lightweight concrete with different mix designs. Jurnal Teknologi, 70(1), 155-159. https://doi.org/10.11113/jt.v70.2507

• Suhendro, B. (2014). Toward green concrete for better sustainable environment. Procedia Engineering, 95, 305-320. https://doi.org/10.1016/j.proeng.2014.12.190

• Tangchirapat, W., & Jaturapitakkul, C. (2010). Strength, drying shrinkage, and water permeability of concrete incorporating ground palm oil fuel ash. Cement and Concrete Composites, 32(10), 767-774. https://doi.org/10.1016/j.cemconcomp.2010.08.008

• Thakrele, M. H. (2014). Experimental study on foam concrete. International Journal of Civil, Structural, Environmental and Infrastructure Engineering Research and Development, 4(1), 145-158.