Design of Rigid Pavement Using Geosynthetic Material

Abstract: The present experimental study investigates the influence of incorporating polypropylene fibre (PPF) as a partial replacement for cement in concrete, with a primary focus on evaluating the mechanical strength and overall performance of the resultant mix. In this research, various percentages of PPF—ranging from 0.5% to 12% by weight of cement—were introduced to examine their effect on concrete properties. The results demonstrate that lower dosages of PPF, specifically 0.5% and 1%, yield a significant improvement in the compressive strength and durability characteristics of concrete when compared to conventional Plain Cement Concrete (PCC). These improvements can be attributed to the fibre's ability to bridge micro-cracks, enhance the ductility, and reduce shrinkage-related issues. However, the study also indicates that increasing the PPF content beyond 2%, particularly in the range of 6% to 12%, results in a marked reduction in strength and performance metrics. This deterioration is likely due to the excess volume of fibre interfering with the homogeneity and workability of the concrete mix, leading to voids and weak zones. As such, it can be concluded that there exists an optimal threshold—up to a maximum of 2%— for the effective and beneficial use of polypropylene fibre in concrete. Beyond the performance benefits, the use of PPF as a cement substitute also offers considerable environmental advantages. Since cement production is highly energy-intensive and contributes significantly to carbon dioxide emissions, reducing its usage through partial replacement with polypropylene fibres contributes to more sustainable construction practices.