Rational Approach for Characterizing In Situ Infiltration Parameters of Two-Layered Pervious Concrete Pavement Systems

Pervious concrete (PC) has gained acceptance as a sustainable pavement material because of its ability to capture and infiltrate stormwater through the pavement system, and subsequently augment groundwater recharge. However, a systematic methodology that estimates and assesses the in situ infiltration characteristics of pervious concrete pavement (PCP) systems has yet to be developed. The objective of this study was to establish a rational methodical approach that evaluates the infiltration rates through PC and granular subbase (GSB) layers in a PCP system by utilizing experimental and analytical techniques. Over 20 field test slabs, each measuring $4\times 4\times 0.15\mathrm{m}$, were constructed along a 120-m long stretch using one single PC mix type overlaid on a 0.25-m GSB layer. An experimental field test was designed to estimate the in situ infiltration rate through the PCP system, and was found to vary between 0.11 and $0.32\mathrm{cm}/\mathrm{s}$. Further, an infiltration test was performed on PC slabs to measure the surface infiltration rate (SIR), which ranged from 0.10 to $1.28\mathrm{cm}/\mathrm{s}$. Using the principle of conservation of mass, which assumes that the flow rate through each layer in a PCP system is identical, the infiltration rate of the GSB layer was found to be $0.07–0.11\mathrm{cm}/\mathrm{s}$. A significant contribution of this study was the development of a generic approach toward characterizing the major in situ infiltration parameters of multilayered PCP systems that incorporate a base and subbase layer, which have the potential to serve as effective hydraulic conduits through the system.