Recruitment of the New LTPP SPS-10:
Warm Mix Asphalt Experiment
Gabe Cimini
LTPP NARSC Project Manager
Presentation Outline
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LTPP Approach to WMA Research
Site Requirements
Roles and Responsibilities
SPS-10 Nomination Process
Why WMA?
• 356 million tons of WMA produced in 2012
– 24% of all plant mix produced in US was WMA
• 35 different WMA technologies
• WMA is a priority innovation under FHWA’s Every
Day Counts (EDC) Initiative
Objectives
• Long-term performance of WMA relative to HMA
• Capture data on WMA with RAP
Benefits to Agencies
• Detailed construction information including a
construction report
• Rigorous materials testing (over multiple
intervals) using latest testing technology
• Ongoing FWD, distress, profile, and texture
monitoring to study short and long term
performance
• Ability to study Agency-specific issues related to
WMA
SPS-10 Requirements
• Overview
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AC overlay of existing AC pavements
2” to 4” overlay thickness
Dense graded mix
RAP content 10-25% (binder replacement)
1 HMA control test section
2 WMA test sections
• Foaming Process
• Chemical Additive
– Tack Coats between lifts
Site Layout Requirements
• WMA:
– Production of ≤ 275°F or
– Production at least 30°F less than HMA
Existing Pavement Requirements
• Uniformity
– Subgrade type/condition
– Base thickness/type
– Bound layer thickness/type
– Surface condition
– Traffic loading
– Pre-overlay repairs based on Highway Agency’s
standard practice
Experiment Layer Requirements
• Mix design/binder grade selection based on
Agency’s standard practice
• Overlay thickness selected by Agency’s standard
practice
• Uniformity between HMA and WMA
– Same binder source/grade
– Same aggregate source/gradations
– Mix design/JMF
Supplemental Sections
• Agencies can build additional test sections that
will be monitored as part of the LTPP program
– Varying levels of RAP
– Additional WMA technologies
– Layer thickness variation
– Open or gap graded mixtures
– Varying aggregate sources/absorption levels
– Other variables of interest to Agency
Roles/Responsibilities
• Agencies
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Nominate project(s)
Validate in-situ conditions
Submit inventory data
Develop plans, specifications, mix design
Provide construction and
inspection/control/management
– Perform materials sampling/patching
– Collect traffic data
– Provide traffic control
Sampling Areas (Draft)
Coring at 0, 6, 12 and 18 months after construction
Traffic Data Collection Guidelines
• Quality traffic data is critical in assessing the vehicle loading on
pavements
– Permanently mounted sensors whenever possible
– As long as a documented calibration plan is followed, data from both
portable and permanent equipment will be accepted (required LTPP
Traffic Sheet 16 – Site calibration summary)
– The agency should plan to repair faulty equipment within 1 month
– At a minimum, 2 weeks of continuous classification data 4 times per
year (a total of 8 weeks of classification data)
– Data to be submitted by the agency on a monthly basis, however, the
data will be accepted if submitted quarterly as well
– If a WMA test site does not have weight data, then the agency must
submit an LTPP Traffic Sheet 10 (Traffic volume and load estimate).
Submitting 1 Sheet 10 per year is sufficient
Roles/Responsibilities
• FHWA
LTPP Data & Information
– Develop experimental
Climate
design/research plan
– Coordinate among Agencies
– Oversee construction data
Materials
collection
Response
– Perform materials testing
– Provide materials sampling support
– Collect performance monitoring
data
– Store, analyze, and report data
Load
Structure
Distress
3
Nomination Process
• FHWA accepting nominations now
• Projects to be constructed in 2014 and 2015
• Nomination forms are available from FHWA and
the LTPP Regional Support Contractors (RSCs)
• FHWA will evaluate nominations and notify
Agencies
• Coordination through LTPP RSCs
Additional Tests on Materials
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Material Testing somewhat limited
Additional information beneficial on national level
Agencies encouraged to perform additional tests
Recommended by the FHWA Asphalt Mixture
Expert Task Group, based upon NCHRP Research
Results Digest 370:
Additional Tests on Materials
Flow Number (AMPT)
AASHTO TP 79
Hamburg Test
AASHTO T 324 (Note: Prepare specimens at air voids content of
7±1% and conduct test at standard conditions: 50°C under
water.)
APA
AASHTO T 340
Dynamic Modulus (AMPT)
AASHTO PP 61
Beam Fatigue
AASHTO T 321
Overlay Test
TxDOT Method: Tex-248-F, Test Procedure for Overlay Test,
February 2014
Simplified Viscoelastic Continuum Damage (S-VECD)
AASHTO TP 107
Superpave Indirect Tension Test (IDT)
University of Florida
Semi-Circular Bending Test at Intermediate Temperatures
Louisiana Transportation Research Center (LTRC)
IDT Creep Compliance and Strength
AASHTO T 322
Semi-Circular Bending Test
AASHTO TP 105
Disk Shaped Compact Tension – DC(T) Test
ASTM D7313
Moisture Sensitivity
AASHTO T 283 (Note: 1 Freeze/Thaw cycle)
Volumetric Properties
AASHTO R 35
Gyratory Compaction to Ndesign
AASHTO T 312
Contact
Information
Name
Agency
Phone
Email
Jack
FHWA-LTPP 202.493.3144 Jack.Springer@dot.gov
Springer
Gabe
Cimini
North Atlantic 716.632.0804 Gabe.Cimini@stantec.com
RSC
EXT. 7470
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