Agré Séraphin Djomo1, Konan Roger Assie2, and Tani Kouadio Florentin3
1 Laboratoire des Sciences et Technologies de l’Environnement, UFR Environnement, Université Jean Lorougnon Guédé, BP 150 Daloa, Côte d’Ivoire
2 UFR Environnement, Université Jean Lorougnon GUEDE, BP 150 Daloa, Côte d’Ivoire
3 UFR Environnement, Laboratoire des Sciences et Technologies de l’Environnement, Université Jean Lorougnon GUEDE de Daloa, B.P 150 Daloa, Côte d’Ivoire
Original language: English
Copyright © 2026 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
This study investigates the influence of the water-to-cement ratio (W/C) on the physical, mechanical, and hydraulic properties of permeable concrete. The raw materials Portland cement, clean lagoon sand, and 5/15 mm gravel were characterized through granulometric analysis, sand equivalent tests, Los Angeles and Micro-Deval resistance, and density measurements. The sand exhibited a fineness modulus of 2.33, a curvature coefficient of 1.02, and a uniformity coefficient of 2.72, confirming its suitability for concrete production. Aggregate resistance values (Los Angeles = 28; Micro-Deval = 5) indicated satisfactory durability. Concrete mixtures were prepared with constant proportions of sand, cement, and gravel, while varying water content to achieve W/C ratios between 0.30 and 0.68. Fresh concrete properties were assessed using the Abrams cone slump test, while hardened concrete was evaluated for porosity, density, compressive strength, tensile strength, and permeability. Results showed that slump increased with W/C, ranging from stiff (0–5 cm) to fluid (>20 cm). Porosity decreased with increasing W/C, stabilizing around 12% at W/C ≥ 0.52, while density peaked at 2.43 g/cm3. Mechanical strength was maximized at intermediate ratios (0.43–0.52), with compressive strength reaching 25.8 MPa and tensile strength 3.24 MPa. Conversely, permeability was highest at low ratios (0.30–0.34, ≈10⁻6 m/s) and dropped to ≈10⁻8 m/s at higher ratios. These findings highlight a fundamental compromise between permeability and strength. For drainage applications such as sidewalks and pavements, low W/C ratios (0.30–0.34) are optimal, while intermediate ratios (0.43–0.52) are preferable for structural performance. The study confirms that tailoring W/C ratios is essential for balancing hydraulic efficiency and mechanical durability, paving the way for future optimization using alternative binders and sustainable materials.
Author Keywords: permeable concrete, water-to-cement ratio, permeability, mechanical strength, porosity, urban pavements.
