Examination of Pervious Pavement Pore Parameters with X-Ray Tomography

• Published in: Journal of environmental engineering (New York, N.Y.) Vol. 141; no. 10
• Main Authors: Kuang, X, Ying, G, Ranieri, V, Sansalone, J
• Format: Journal Article
• Language: English
• Published: American Society of Civil Engineers 01-10-2015
• Subjects: Technical Papers
• ISSN: 0733-9372; 1943-7870
• DOI: 10.1061/(ASCE)EE.1943-7870.0000826

AbstractPervious pavement (PP) is an infrastructure material that can alter rainfall-runoff relationships, filter particulate matter (PM), and sequester runoff constituents. Beyond a measure of total porosity (ϕt), less-commonly measured pore parameters and relationships thereof influence these phenomena. In this study, cementitious PP (CPP), used as a permeable surface for an exfiltration system loaded by runoff, was examined. X-ray tomography (XRT) was utilized to examine pore size and frequency, generate a total-to-effective porosity (ϕt−ϕe) relationship, quantify pore tortuosity (Le/L), and relationships for specific surface area (SSA), pore-size distributions (PSD)pore, and ϕt. Gravimetric analyses were used for SSA based on mass (SSA)s as well as validation of XRT porosity. Results indicate that ϕt ranged from 10 to 30% while ϕe ranged from 4 to 27%. Relationships for (ϕt−ϕe), SSA, ϕt, and median pore diameter (d50n) were represented with a power law model (PLM). Using ϕt the (SSA)pt of pores ranged from 11,000 to 19,000  m2/m3 while for ϕe, (SSA)pe ranged from 12,000 to 21,000  m2/m3. XRT results show that the (PSD)pore is hetero-disperse. (Le/L) ranged from 2.9 to 5.9, compared to 1.4 for a monodisperse and uniform distribution of pore sizes. The (Le/L)-ϕt relationship and probability density function (pdf) of (Le/L) were Gaussian. Beyond the common index of ϕt, these parameters are building blocks for infiltration, filtration, evaporation, storage, and reaction components of models such as the storm water management model (SWMM) and computational fluid dynamics (CFD).