Asphalt Pavement Magazine - May/June 2018 - 23

Engineer at Hennepin County
Public Works, this type of ongoing
research came in handy during a
pavement maintenance project in
September 2017.
Paul Nolan, the Research Project
Supervisor in the Office of Materials
and Road Research for MnDOT,
explained that he was driving a
section of County Route 61 when
he noticed the Hennepin County
Public Works crew performing
roadwork that could test a material
he had on hand. He learned that
the county used 35 percent RAP in
the pavement mixture without any
additive, so he offered to Elsner the
tote of Delta S asphalt rejuvenator he
had from Collaborative Aggregates
LLC in Wilmington, Mass.
Nolan explained that the oneyear-old NCAT and MnROAD
partnership allows the entities
to mirror test sections on their
respective research sites. Because
Collaborative Aggregates sponsored
test sections to gather data on
the use of its plant-based Delta S
rejuvenator, Nolan had a tote of
the product "left over" from the
MnROAD test sections. He shared
that MnDOT originally looked for

a pavement maintenance project
where they could use the additive
to test pavement performances with
live traffic. When a candidate milland-overlay project in downtown
Minneapolis didn't pan out, Nolan
happened upon the Hennepin
County mill and overlay.
According to Elsner, the project
on Northwest Boulevard (CSAH 61)
from just north of Schmidt Lake
Road to Bass Lake Road (CSAH 10) in
Plymouth will have a side-by-side test
with two lanes northbound using the
typical mix and the two southbound
lanes having mix treated with Delta
S. The dense-graded mix will be
paved at 1.5 inches compacted as
a riding course. "This location was
selected to also give the county a
comparative test as the pavement to
the south of this project was overlaid
earlier in the 2017 season with the
typical mix," said Elsner.
Elsner has been with the county
for two years and with MnDOT
for six years prior to that, so she is
well versed in Minnesota's desire to
improve conditions for motorists
while improving sustainability. "The
county has a goal of 67 percent or
better on our ride-rating system,
which we will achieve at the end
of this year [2017]," Elsner said. To
date, pavement maintenance has
consisted mostly of mill and fill,
she said. "We've performed thin

mills and overlays of 1.5 to 2 inches
to improve rideability. We've been
using the same mix, an MV3, with
35 percent RAP."
For some maintenance overlay
projects, the county hires a
subcontractor that makes a Marshall
mix that also uses 30 to 35 percent
RAP; Elsner stated that cracking
is the performance characteristic
that has remained problematic
with those mixes as well. "We've
noticed a similar cracking pattern
across the board," she said. The 1.3mile stretch of CSAH 61 wasn't in
poor condition, but the proactive
public works team had reasons
to select it for both maintenance
and a rejuvenator proving ground.
"This section of road was originally
constructed in 1992, chip sealed in
1996, and the last treatment was a
2-inch mill and overlay in 2005,"
Elsner shared. In 2016, it received
a pavement condition rating (PCI)
of 37 on a scale of 0 to 100, and
a pavement surface rating (PSR)
of 2.55 on a scale of 0 to 4.00.
"Moderate transverse cracking and
minor rutting were noted along with
oxidation of the mat," Elsner said.
J. Richard Willis, Ph.D.,
Director of Pavement Engineering
& Innovation at NAPA, reminded
readers why that's a concern for
agencies. "The quality of the binder
continued on page 25

From left, Paul Nolan of MnDOT, Joe Hannan of Hennepin County, Trudy Elsner of Hennepin County,
and Jerry Geib of MnDOT visited the County Route 61 project during the paving operation.
Asphalt Pavement Magazine - May/June 2018 * 23



Asphalt Pavement Magazine - May/June 2018

Table of Contents for the Digital Edition of Asphalt Pavement Magazine - May/June 2018

Chairman’s Commentary
Industry News
Tools for the Trade
A Green Answer for Higher Recycling
Reducing Rolling Resistance to Reduce Emissions
Recycled Tire Rubber Mixture Yields High-Performing Road
The Pavement Economics Committee: A Powerful Partnership
Focus on the Field: Job Spotlight
Industry Events
Index of Advertisers/Advertisers.com
Perspectives
Asphalt Pavement Magazine - May/June 2018 - intro
Asphalt Pavement Magazine - May/June 2018 - cover1
Asphalt Pavement Magazine - May/June 2018 - cover2
Asphalt Pavement Magazine - May/June 2018 - 3
Asphalt Pavement Magazine - May/June 2018 - 4
Asphalt Pavement Magazine - May/June 2018 - 5
Asphalt Pavement Magazine - May/June 2018 - 6
Asphalt Pavement Magazine - May/June 2018 - 7
Asphalt Pavement Magazine - May/June 2018 - 8
Asphalt Pavement Magazine - May/June 2018 - Chairman’s Commentary
Asphalt Pavement Magazine - May/June 2018 - 10
Asphalt Pavement Magazine - May/June 2018 - Industry News
Asphalt Pavement Magazine - May/June 2018 - 12
Asphalt Pavement Magazine - May/June 2018 - 13
Asphalt Pavement Magazine - May/June 2018 - 14
Asphalt Pavement Magazine - May/June 2018 - 15
Asphalt Pavement Magazine - May/June 2018 - 16
Asphalt Pavement Magazine - May/June 2018 - 17
Asphalt Pavement Magazine - May/June 2018 - Tools for the Trade
Asphalt Pavement Magazine - May/June 2018 - 19
Asphalt Pavement Magazine - May/June 2018 - 20
Asphalt Pavement Magazine - May/June 2018 - 21
Asphalt Pavement Magazine - May/June 2018 - A Green Answer for Higher Recycling
Asphalt Pavement Magazine - May/June 2018 - 23
Asphalt Pavement Magazine - May/June 2018 - 24
Asphalt Pavement Magazine - May/June 2018 - 25
Asphalt Pavement Magazine - May/June 2018 - 26
Asphalt Pavement Magazine - May/June 2018 - 27
Asphalt Pavement Magazine - May/June 2018 - Reducing Rolling Resistance to Reduce Emissions
Asphalt Pavement Magazine - May/June 2018 - 29
Asphalt Pavement Magazine - May/June 2018 - 30
Asphalt Pavement Magazine - May/June 2018 - 31
Asphalt Pavement Magazine - May/June 2018 - Recycled Tire Rubber Mixture Yields High-Performing Road
Asphalt Pavement Magazine - May/June 2018 - 33
Asphalt Pavement Magazine - May/June 2018 - 34
Asphalt Pavement Magazine - May/June 2018 - 35
Asphalt Pavement Magazine - May/June 2018 - 36
Asphalt Pavement Magazine - May/June 2018 - 37
Asphalt Pavement Magazine - May/June 2018 - 38
Asphalt Pavement Magazine - May/June 2018 - 39
Asphalt Pavement Magazine - May/June 2018 - The Pavement Economics Committee: A Powerful Partnership
Asphalt Pavement Magazine - May/June 2018 - 41
Asphalt Pavement Magazine - May/June 2018 - 42
Asphalt Pavement Magazine - May/June 2018 - 43
Asphalt Pavement Magazine - May/June 2018 - 44
Asphalt Pavement Magazine - May/June 2018 - 45
Asphalt Pavement Magazine - May/June 2018 - 46
Asphalt Pavement Magazine - May/June 2018 - 47
Asphalt Pavement Magazine - May/June 2018 - Focus on the Field: Job Spotlight
Asphalt Pavement Magazine - May/June 2018 - 49
Asphalt Pavement Magazine - May/June 2018 - 50
Asphalt Pavement Magazine - May/June 2018 - 51
Asphalt Pavement Magazine - May/June 2018 - Industry Events
Asphalt Pavement Magazine - May/June 2018 - 53
Asphalt Pavement Magazine - May/June 2018 - 54
Asphalt Pavement Magazine - May/June 2018 - Index of Advertisers/Advertisers.com
Asphalt Pavement Magazine - May/June 2018 - 56
Asphalt Pavement Magazine - May/June 2018 - 57
Asphalt Pavement Magazine - May/June 2018 - Perspectives
Asphalt Pavement Magazine - May/June 2018 - cover3
Asphalt Pavement Magazine - May/June 2018 - cover4
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