Comprehensive investigation of permeability characteristics of pervious concrete: A hydrodynamic approach

• Determined permeability of eighteen pervious concrete mixtures with varying heads.
• Discussed contribution of various mix parameters in respect of permeability.
• Quantified and described nonlinearity in Darcy’s law for PC mixes through Izbash/power law.
• Utilized a modified Kozeny-Carman equation to discuss effect of macroporous features.
• Recommended a promising hydrodynamic approach to rationally design pervious concrete pavements.

Pervious concrete (PC) mixtures were designed and prepared to measure and study permeability characteristics at varying head levels using a falling head permeameter. A total of 1092 readings was used to study the permeability properties of eighteen PC mixtures whose porosity was in the range of 15–37%, and permeability in the realm of 0.076–3.5 cm/s. The permeability reduced as the head of water increased, and gradually attained an asymptotic relation with the head. Cement-to-aggregate ratio had largest contribution in controlling permeability of PC mixtures. Nonlinearity in Darcy’s law was observed in respect of permeability of PC mixes, which was modelled using Izbash/power law, and was prominent for gradations consisting of larger sized aggregates due to inconsequential tortuous pore structure. Modified Kozeny-Carman equation was fitted for PC gradations to compare the results with Izbash law, which showed good agreement. This study is deemed to assist in understanding the hydrodynamics of water flow in pervious concrete, which in turn will aid in rational pervious concrete pavement system designs.