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.

Embedded infiltration rings have been historically used to estimate the infiltration properties of pervious concrete (PC) pavements. However, no methodical study has evaluated the effect of the size of embedded rings on the infiltration characteristics of these special pavement systems. The objective of this research was to assess the infiltration rate of PC using a multi-scale, in situ approach through embedding rings of various sizes in pavement slabs. Essentially, this investigation attempted to identify the most appropriate size of the embedded ring that can estimate infiltration rates of PC slabs in a reliable manner. To meet the proposed objective, a multi-scale in situ experimental program was designed, in which five infiltration rings of inner diameter ranging from 100 to 580 mm were embedded into three PC slabs of dimensions 3 × 2.5 × 0.15 m. A surface infiltration test was also conducted on PC slabs and was found to vary from 0.36 to 1.87 cm/s. The embedded infiltration rate (EIR) was estimated using a falling head permeability test by ponding water above the pavement surface and measuring the time taken to drain. EIRs decreased from 1.36 to 0.27 cm/s with increasing ring diameter from 100 to 580 mm. Field tests also indicated that infiltration rates for smaller ring diameters (180 mm and lower) had higher uncertainty, which was attributed to the inability of achieving optimum compaction efforts inside of smaller rings. Based on the findings, the optimum size for estimating the infiltration rate of PC was found to be 270 mm. It is noteworthy that this diameter is in the range suggested by ASTM C1701, Standard Test Method for Infiltration Rate of In Place Pervious Concrete, i.e., 300 mm. This research helped identify the practicable specimen size that could be utilized by researchers and practitioners to estimate the most reliable field infiltration rates through PC.