Structural Performance of Polypropylene Fibre-Reinforced Concrete in Road Kerb and Channel Drain Applications in Enugu State

The use of fibre reinforcement in concrete for small infrastructure elements such as road kerbs and channel drains offers potential improvements in impact resistance, crack control, and durability over conventional plain concrete. This study evaluates the structural performance of polypropylene fibre-reinforced concrete in these applications, using a laboratory-to-field assessment approach in Enugu State in the South East geopolitical zone. Polypropylene fibres at dosages of 0.5, 1.0, and 1.5 kg/m3 were added to a standard C25 concrete mix, and specimens were tested for compressive strength, flexural strength, split tensile strength, and impact resistance in accordance with ASTM standards. In parallel, kerb and drain channel units were cast with and without fibre reinforcement and installed at two road construction sites in Enugu North for field performance monitoring over twelve months. Results indicate that polypropylene fibres at 1.0 kg/m3 improved flexural strength by twenty-two percent and impact resistance by thirty-eight percent relative to the plain concrete control, with negligible reduction in compressive strength. Field-installed kerb units without fibre reinforcement showed chipping and corner cracking from vehicle impact within the first three months, while fibre-reinforced units remained undamaged over the full monitoring period. The cost premium of polypropylene fibre incorporation at the optimum dosage was estimated at approximately 3,200 Naira per cubic metre, which the study concludes is justified by the improved durability and reduced maintenance cycle. Recommendations include adoption of polypropylene fibre-reinforced concrete as a standard specification for road drainage elements in Enugu State. Keywords: polypropylene fibres, fibre-reinforced concrete, road kerbs, Enugu State, impact resistance.