Optimization of Porous Pavement Mix Designs for Installation and Durability
Under 1 year
Research Idea Scope
Porous pavement usage and design has improved dramatically since 2002 (Kandhal and Mallick, 2002) with published guidelines on mix designs (NAPA 2003) with continued refinements (UNHSC 2009) and others. The use of porous pavements in a transportation setting vary from parking lots, to road shoulders, low use roads, to moderate use state roads. However, porous pavement failures still abound and can generally be traced to either poor mix design or poor installation practices. While improvements have been made, important deficiencies still remain. Recent studies have shown that porous pavements can result in substantial total project cost savings of 6-26% due to reduction of stormwater infrastructure (Gunderson 2010). This task will address the following items: 1) Evaluation of asphalt grade with modifiers for durability, 2) Aggregate gradation as it relates to clogging and materials strength, 3) determination of QA/QC parameters, 4) Assessment of installation practices (compactive effort and temperature) as they relate to durability and void space, 5) Variations in mix design based on durability needs and usage requirements (e.g. low use, high use roadways), 6) determination of long-term creep characteristics for pavement design in relation to void space and infiltration capacity, 7) determination of appropriate durability measures for abrasion and strength.
Important benefits exist for the usage of porous pavements for both transportation and stormwater management needs. The substantial limitations in current mix designs can be addressed through a pavement design optimization process that utilizes a thorough evaluation of the influence of asphalt grade, admixtures, aggregate gradation, and installation practices upon pavement performance. A substantial body of knowledge can be applied from the design of open graded friction courses (Cooley et al 2009). Important differences exist between full depth OGFC and wearing course only applications. Limitations exist in the application and selection of performance measures and in particular for durability and strength. Performance methods development and refinement will be an integral component of pavement design optimization.
Cooley, L. A., Brumfield, J. W., Mallick, R. B., Mogawer, W. S., Partl, M., Poulikakos, L., and Hicks, G. (2009). “NCHRP Report 640: Construction and Maintenance Practices for Permeable Friction Courses.” Transportation Research Board.
Gunderson, J. (2010-In preparation). “Boulder Hills LID Economic Case Study”, “Greenland Meadows LID Economic Case Study”, Forging the Link Between Research-Based Institutions, Watershed Assistance Groups, and Municipal Land Use Decisions, UNH Stormwater Center, Durham.
Kandhal, P., and R. Mallick. (2002). “Design, Construction and Maintenance of Open-Graded Asphalt Friction Courses: Information Series 115.”
NAPA. (2003). “Design, Construction, and Maintenance Guide for Porous Asphalt Pavements.” Information Series 131, National Asphalt Pavement Association.
UNHSC, Roseen, R. M., Ballestero, T. P., Briggs, J. F., and Pochily, J. (2009). “UNHSC Design Specifications for Porous Asphalt Pavement and Infiltration Beds.” University of New Hampshire Stormwater Center, Durham, NH.
Urgency and Payoff
Products: Technical documents: 1) porous pavement mix design based on durability and usage requirements, 2) porous pavement installation guidance, 3) recommendation of durability and strength performance measures for porous pavement
Changes: Clear guidance on the applicability, cost, and maintenance for porous asphalt pavements.
Outcomes: Improved ease and cost of DOT compliance with stormwater management requirements.
Robert Roseen PhD, PE, D.WRE, University of New Hampshire Stormwater Center