Increased environmental awareness and the demand for sustainable materials have promoted the use of more renewable and eco-friendly resources like natural fibre as reinforcement in the building industry. Among various types of natural fibres, kenaf has been widely planted in the past few years, however, it hasn’t been extensively used as a construction material. Kenaf bast fibre is a high tensile strength fibre, lightweight and cost-effective, offering a potential alternative for reinforcement in construction applications. To encourage its use, it’s essential to understand how kenaf fibre’s properties affect the performance of cement-based composites. Hence, the effects of KF on the properties of cementitious composites in the fresh and hardened states have been discussed. The current state-of-art of Kenaf Fibre Reinforced Cement Composite (KFRCC) and its different applications are presented for the reader to explore. This review confirmed the improvement of tensile and flexural strengths of cementitious composites with the inclusion of the appropriate content and length of kenaf fibres. However, more studies are necessary to understand the overall impact of kenaf fibres on the compressive strength and durability properties of cementitious composites.

Water permeability of cement-based concrete has been recognized as a critical intrinsic property highly affecting the durability of reinforced concrete. An experimental study was done, designed to examine the water permeability and setting time of Portland cement mortar with nano-SiO₂ admixed at 0.5, 1, 1.5, and 2 wt% of cement. The percentage, velocity, and coefficient of water absorption tests results showed that the incorporation of nano-SiO₂ particles improved the water penetration resistance of the binary-blended concrete. Such improvements were especially significant when using 2 wt% of nano-SiO₂. The experimental results revealed that the admixing of nano-SiO₂ particles not only led to denser cement mortar but also changed the morphology of cement hydration products. Mechanisms were proposed to explain the physicochemical changes induced by the nano-SiO₂ particles and the specific surface area of them is demonstrated as one of the key factors. Considering the higher strength and durability is promising their use in binary-blended concrete.