Recruitment of the New LTPP SPS-10: Warm Mix Asphalt Experiment Gabe Cimini LTPP NCRSC Project Manager

Presentation Outline 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 – 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 – 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 – Develop experimental design/research plan – Coordinate among Agencies – Oversee construction data collection – Perform materials testing – Provide materials sampling support – Collect performance monitoring data – Store, analyze, and report data

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 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 N design AASHTO T 312

NameAgencyPhone Jack Springer FHWA-LTPP Gabe Cimini North Central RSC EXT Contact Information

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