Porous Asphalt The Specs Tim Horton, Skillings Connolly Jessica Knickerbocker, City of Tacoma Mark...
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Porous Asphalt The Specs Tim Horton, Skillings Connolly Jessica Knickerbocker, City of Tacoma Mark A. Palmer, P.E., LEED AP, City Engineer, City of Puyallup WAPA October 28, 2014
Porous Asphalt The Specs Tim Horton, Skillings Connolly Jessica Knickerbocker, City of Tacoma Mark A. Palmer, P.E., LEED AP, City Engineer, City of Puyallup
Porous Asphalt The Specs Tim Horton, Skillings Connolly Jessica
Knickerbocker, City of Tacoma Mark A. Palmer, P.E., LEED AP, City
Engineer, City of Puyallup WAPA October 28, 2014
Slide 2
Porous Asphalt: The Specs Why? Who? Site Design Materials and
Specifications Construction Sequencing Whats Next? October 28, 2014
Porous Asphalt -The Specs Washington Asphalt Paving Association 2
Icon Paving Cheney Stadium
Slide 3
Why do we need a standard spec? $66 Million Grants Failing
Roadways Stormwater Regulations Puget Sound Contractor Complaints
No Industry Standards October 28, 20143 Porous Asphalt -The Specs
Washington Asphalt Paving Association
Slide 4
Partners 4 Porous Asphalt -The Specs Washington Asphalt Paving
Association October 28, 2014
Slide 5
Site Design October 28, 2014 Porous Asphalt -The Specs
Washington Asphalt Paving Association 5
Slide 6
Mix Design October 28, 2014 Porous Asphalt -The Specs
Washington Asphalt Paving Association 6 WSDOT specifications for
Class HMA PG 70-22 (Polymer modified) with the following
modifications: Binder content shall be between 6.0% and 7.0% by
weight of total (dry aggregate) mix, and will be the highest
percentage that meets 0.3% maximum drain down test (ASTM D6390-05)
Void ratio of 16% to 25% (ASTM D3203) requirements tests at 75
gyrations (Ndesign = 75) or higher. The contractor shall adjust the
aggregate to meet the maximum drain down test requirements within
the ranges provided in section 9-03.8.
Slide 7
Drain Down Drain Down-ASTM D6390-05, 0.3% maximum @ 15 above
design mix temperature ODOT has alternate ODOT TM 318 Drain Down
Test-subjective Consider adding fiber to mix design if draindown is
excessive Still working on a good test Porous Asphalt -The Specs
Washington Asphalt Paving Association 7 October 28, 2014 Tucci
Paving Clay Huntington Way
Slide 8
Gradation SievePercent Passing 100 90-100 3/855-85 No. 410-25
No. 80-13 No. 2000-5 The aggregate should consist of crushed stone
Other aggregates can be acceptable, both larger and smaller.
Percent of two face fracture shall be greater than 90%. Fines can
be increased to meet Drain Down Test and make porous mix more
manageable at the production plant. Porous Asphalt -The Specs
Washington Asphalt Paving Association October 28, 2014
Slide 9
Construction Prior to Paving Porous Asphalt Treated Based
Instead of choker course Maintain access on permeable ballast Watch
materials and placement: Look for aggregate to be porous, no sheen
or sealed off areas Porous Asphalt -The Specs Washington Asphalt
Paving Association 9October 28, 2014 Permeable Ballast
Slide 10
Watch for asphalt in the beds of delivery trucks-indicates
drain down issue. Porous mix producers can often utilize warm mix
technology if necessary. Rollers are on the asphalt in the correct
temperature range (by mix design). Usually about 25 o F below dense
graded mixes. Rollers are using vibratory compaction correctly
(assuming test were passed during mix design) Establish firm/
unyielding roller pattern - Guard against over compaction.
September 24, 2014 WSU Puyallup Technical Workshop Series-
Permeable Pavement Design 10 Construction Paving Day
Slide 11
Construction Acceptance Infiltration rate modified ASTM test
(C1701) Initial tests should average over 200/hour City of Puyallup
and Tacoma testing existing densities of porous asphalt to see if
density range can be established for porous asphalt. If range can
be established, will help inspectors with controlling compaction to
desire range Look for sealed of areas in pavement. Porous Asphalt
-The Specs Washington Asphalt Paving Association 11October 28,
2014
Slide 12
Goals Improve Pavement Durability Develop a Standard Spec for
Western Washington Move to a performance specification. Evaluating
Batching and Lay Down Temperatures Looking at alternative tests
used throughout the country that better reflect the final product.
October 28, 2014 Porous Asphalt -The Specs Washington Asphalt
Paving Association 12
Slide 13
Mark A. Palmer, P.E., LEED AP City Engineer City of Puyallup
(253) 435-3606 [email protected][email protected]
13 Porous Asphalt -The Specs Washington Asphalt Paving Association
October 28, 2014 Contact Information Jessica Knickerbocker Project
Manager City of Tacoma (253) 502-2119 [email protected][email protected] Tim Horton, P.E. Project Engineer
Skillings Connolly (253) 435-3606 [email protected][email protected]