Influence of aggregate gradation on the performance of fibre-reinforced pervious concrete

The influence of aggregate gradation on the performance of pervious concrete (PC) mixes was investigated, employing aggregates of nominal sizes 4.75–9.5 mm, 9.5–12.5 mm and 12.5–20 mm. The effects of polypropylene fibre (PF) and glass fibre (GF) were also examined, varying their volumetric proportions from 0.1% to 0.4% in increments of 0.1%. For all the mixes, the cement-to-aggregate ratio was held constant at 0.30, while the water-to-cement ratio was maintained at 0.34. The addition of PF or GF to the PC mixes resulted in a slight improvement in compressive strength (f c ), in the range ≈0.3–2.6%. With optimal percentages of the fibres (0.3% PF, 0.2% GF), the increase in flexural strength (f cr ) and split tensile strengths (f st ) was 1–6% across all mixes. While the fibre reinforcement slightly enhanced f cr and f st , it had no significant impact on f c , porosity (P), permeability coefficient (k), sulfate resistance and abrasion resistance. The smaller aggregate size enhanced mechanical properties and abrasion resistance through increased particle interlocking and surface contact, but reduced the porosity and permeability of the PCs. A regression model was developed to correlate k–P, f c –P and weight loss due to abrasion and Cantabro revolutions. The model demonstrated a high degree of accuracy.