Transcript New Jersey Department of Transportation Update 2011

Presented at: Rutgers Asphalt Paving Conference
March 8, 2011
Presented by: Eileen Sheehy, P.E.
Manager, Bureau of Materials
NJDOT
Topics for Discussion
 Warm Mix Asphalt
 Independent Assurance Coring
 Ride Quality Specification
 Asphalt Binders for Performance Based Mixes
 Current HMA Research
 Performance Based Specifications
 RAP in HMA
 Northeastern States’ RAP Pooled Fund Study
Warm Mix Asphalt
 NJDOT has done some warm mix asphalt trials over
the past 3 years. Most extensively used to aid in
compaction for late season paving or in specialty mixes
to reduce the laydown temperature.
 All trials used additives – either surfactants or waxes.
 FHWA support of WMA as part of Every Day Counts
initiatives. http://www.fhwa.dot.gov/everydaycounts/
 NJDOT/NJAPA/FHWA Task Force established
November 2010 to implement WMA on NJDOT
projects.
Warm Mix Asphalt Task Group
 Task Group is working on a specification to be put out
for bid on 3-6 projects this coming year.
 Proposed specification allows a trial of any WMA
technology. Extra samples are need of both the WMA
and the HMA on the project to further the research
being done.
 In addition, NJDOT will entertain proposals from
contractors to try WMA on projects that call for HMA
mixes.
 Foaming systems will be considered.
NEAUPG WMA Task Group
 The Northeastern Asphalt User/Producer Group has
formed a task group to consider a more uniform
approach to WMA in the Northeast.
 Preliminary discussions are to have a region-wide
approved products list (or qualified products list).
 Consideration is being given to following the NYDOT
protocols for approving technologies.
 Task Group has been working on a definition of WMA.
Independent Assurance Program
for Coring
 NJDOT will continue the Independent Assurance
Program for Coring in 2011.
 FHWA requires IA on Federally funded projects.
 NJDOT usually uses the same IA Programs on State
funded projects.
 NJDOT has a Consultant on board to take
Independent Cores for testing in the NJDOT
Laboratory and perform analysis of the results.
Ride Quality Specification
 Presentation from last year gave the background of the
new IRI specification for pavements.
 Set targets based on number of lifts of paving, IRI of
existing road, etc.
 Based on the amount of “impediments” (obstacles to
good paving), lots will be excluded from pay
adjustment.
 Expect to see the new specification in all future
projects, so please review the special provisions for
projects to know what the ride quality specification is
for a project.
New IRI Specification Example
Excluded
Lots
Pay Equations for Pavement Ride
Quality for 0.01 Mile
Route 00 NB
MP 5.0 to MP 10.0
1 in Lane 1
3 in Lane 2
IRI < 28
PA = $50
28 < IRI < 48
PA = $120.00 – ($2.5 x IRI)
---------------------Route 00 SB
MP 10.0 to MP 5.0
------------2 in Lane 1
15 in Lane 2
48 < IRI < 58
PA = $0
58 < IRI < 128
PA = (IRI – 58) x (– $7.1429)
IRI > 128
Remove & Replace
Setting the Target IRI
The proposed model is of the following form:
IRISPECIFIED = (IRIBASELINE) • (A1) • (A2) • (A3) • … • (Ak)
Where,
IRIBASELINE = standard level of IRI desirable for payadjustment = $0.0
IRISPECIFIED = adjusted level of IRI to be specified based
on project-specific conditions
Ai = factors (variables) that are project specific
k = Number of different factors in the equation
Generalized Factors
Factor
Symbol
Speed Limit (MPH)
AS
No. of Operations
AO
Existing Roughness (IRI)
AE
Composite Pavement
AC
Speed Limit Factors
Factor for Number of Operations
 Number of operations is defined as the
number of improvement events.
 For example, milling 2" followed by an
overlay of 2" is considered to be 2
operations.
 Or, milling 2" followed by paving 2" of
intermediate and 2" of surface is
considered to be 3 operations.
Factor for Existing Roughness
 This factor recognizes the difficulties in
achieving a smooth pavement when the existing
pavement is rough.
 The “number of operations” (AO) and the
“existing roughness” (AE) are inter-connected
factors and consideration of both factors
contribute to determining the target IRI.
Combined Number of Operations
and Existing Roughness Factor
Composite Pavement Factor
 If the overlay on bare PCC
pavement is > 8", exclude
using a composite
pavement factor.

If an existing overlay is to
be resurfaced with or
without milling, the
composite pavement factor
should not be applied if the
total HMA thickness is > 8“
after the overlay.
Localized Factors Used to
Determine Excluded Lots
Example of Excluded Lots
Calculations
New IRI Specification Example
Excluded
Lots
Pay Equations for Pavement Ride
Quality for 0.01 Mile
Route 00 NB
MP 5.0 to MP 10.0
1 in Lane 1
3 in Lane 2
IRI < 28
PA = $50
28 < IRI < 48
PA = $120.00 – ($2.5 x IRI)
---------------------Route 00 SB
MP 10.0 to MP 5.0
------------2 in Lane 1
15 in Lane 2
48 < IRI < 58
PA = $0
58 < IRI < 128
PA = (IRI – 58) x (– $7.1429)
IRI > 128
Remove & Replace
Asphalt Binders for Performance
Based Mixes
 When the specification for a mix is based on
performance testing of the mix (e.g., BRIC, BRBC,
BDWSC), the actual binder needed will depend on the
mix design.
 A minimum grade binder is listed in the specification,
but the precise binder that will be needed will depend
on the mix design, the formulation of the binder, and
the performance testing of that mix.
Asphalt Binders for Performance
Based Mixes
 With an optimized mix design, a less modified binder
may work, but a more modified binder may be needed
if the mix design is not optimum.
 HMA Supplier should work with the Binder Supplier
to develop a mix that will meet all performance testing
for the mix.
Performance Based Specifications
Research
 New research project starting this year to look at the
following:
 Existing NJDOT performance based mix requirements.
 Performance based specifications for “regular” mixes.
 Use of performance based specifications to eliminate
prescriptive aspects of NJDOT specifications.
 Research being done by Rutgers.
 Research is expected to last 2 years.
RAP in HMA Research Project
 Study being done by Rowan University.
 2 year study will be complete July 2011.
 Findings to date:
 There is incomplete blending of the RAP binder with the
virgin binder. Only partial credit should be considered
for the RAP binder.
 Quality Control is important. Amount of RAP allowed
should be linked to variability of the RAP stockpile.
Northeastern States’ RAP Pooled
Fund Study
 Many of the Northeastern States (including NJDOT)
are involved in a Pooled Fund Study looking at use of
higher percentages of RAP (>25%).
 Work being done at University of New Hampshire
with assistance by Rutgers University.
Thank you for your attention!
[email protected]