Abstract
Fiber reinforced cementitious composites provide higher strength, lower weight, and higher toughness, and have consistently been employed in engineering applications. This research focused on the combined effect of nano silica with sisal fibres in concrete. Sisal Fiber-reinforced concretes offer measurable improvements in tensile strength, deformability, and durability, as well as moderate enhancement in compressive strength, when compared to ordinary concrete. Around 90 specimens were tested for mechanical properties and 48 specimens were evaluated for durability performance to ensure statistical reliability. Different lengths of constant 1.5% sisal fiber (6, 12, and 18 mm) and constant 3% nano silica are substituted in conventional concrete. Tensile, flexural, and compressive strengths were measured through laboratory tests, and durability performance was assessed using chloride penetration and acid resistance tests. Concrete with 1.5% sisal fibres (12 mm length) and 3% nano silica showed enhanced mechanical strength, with percentage improvements of 7.8% in compressive strength, 16.8% in tensile strength, and 19.2% in flexural strength compared to conventional concrete, while the mix with 1.5% sisal fibres (18 mm length) and 3% nano silica exhibited improved durability compared to conventional concrete. As a result, sisal fibres and nano silica can be used to make low-cost, low-energy-consumption concrete with potential applicability in non-structural and semi-structural concrete elements where enhanced durability and crack resistance are required.