1 The Stormwater-Pavement Interface in Cold Climates Washington State University: L. Haselbach/ S, Nassiri

2 Background  Many cold climate stakeholders interested in using low impact technologies such as pervious concrete for managing stormwater quantity and quality.  Their durability under winter and snow-removal conditions are not well understood.  The impact on neighboring pavements with respect to frost heave, etc. and the constraints on storing water below grade in cold climates are not well understood.

3 Project Scope  Objective - assess wintertime impacts on pervious concrete and influence of storing water below grade on neighboring soils/pavements 1Install soil moisture/temperature probes next to a placement 2Monitor surface conditions of permeable and neighboring pavements over winter conditions 3Assess functionality of pervious concrete after use in cold climates

 Site 1: Pervious concrete sidewalk built by WSU in Pullman near Community Hall in May 2015  Site 2: Porous asphalt parking area to be built by the City of Spokane at the arboretum…..tentative July 2015 Objective 1: Soil Moisture Installations 4

 Part of an Ecology project is the match for the work herein, funding the sensor installations in Pullman.  WSU Facilities has funded the new placement on the campus.  The City of Spokane is funding the new placement in Spokane.  This project funds the sensor installation in Spokane. Collaborations for Objective 1 5

 Ongoing pavement condition index evaluation of pervious concrete placements in Pullman after multiple winters (found change in de-icer might have had impacts).  Novel experiment for enhancing micro- texture of pervious concrete surfaces to increase winter skid resistance initiated. Objective 2: 6

Laboratory Specimens: Located Outside by Sloan in Winter: Qualitative Results 7

Laboratory Specimens: Located Outside in Past Winter: Quantitative Lab Results 8 A- broom, b-sand pre-compact, c-Gator, d-sand post, e-control

 All pervious concrete and porous asphalt installations at WSU Pullman have been evaluated for hydraulic functionality.  Sloan pervious concrete sidewalk has been evaluated for cold weather impacts on infiltration over the winter. Objective 3: 9

 Proceedings of LID Conference in Houston January 2015: L.M. Haselbach and B.S. Werner, Pervious Concrete Performance in Eastern Washington: Surface Infiltration  Working on two papers for TRB submittal (by August ) for January 2016 meeting. On impact of temperature on pervious concrete infiltration rate. On the developing friction tests (qualitative and quantitative) to evaluate different pervious concrete microsurfaces for improved winter performance. Products 10

 If the construction goes as planned in Spokane then we expect the project to be complete by the end of the summer.  Then we will be soliciting funds to: collect, evaluate and begin modeling the data from the two sensored sites. And to do the friction analyses on the Community site under winter conditions! Timeline 11

 Dr. Nassiri is proposing detailed heat transfer testing of pervious concrete. We were able to install temperature sensors in the pavement at the new Community site for her work in addition to the proposed laboratory tests. Ancillary 12

Community Placement ..

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Placement Community Placement Done in seven days! Already tested Infiltration rates and They are great! Sand finish slightly Slower!