Activities as TurnerFairbank Highway Research Center Jack Youtcheff

Activities as Turner-Fairbank Highway Research Center Jack Youtcheff Materials & Construction Team Federal Highway Administration www. TFHRC. gov

What’s Go’in On • Modified Binder Research Program – ALF ‘ 93, 90 -07, ALF ‘ 01, PG 67 -80 Study • Phosphoric Modification of Asphalt Binders – AASHTO SOM, Binder ETG • Evaluation of Moisture Damage – 3 D Flow Models, Fundamental Chemistry • Warm Mix Asphalt – WHO, IARC, EPA, NAPA, NCAT, FHWA

Experiment Objectives • Primary – Refine Superpave for Modified Binders • Secondary, Evaluate… – M-E Pavement Design Guide – Crumb Rubber-Modified Asphalts • Arizona and Terminal Blend Processes – Simple Performance Test

Final Test Matrix… AZ PG PG CRM Air TX 70 -22 PG SBS Air SBS T-P 70 -22 ---Blown TBCR + 70 -2264 -40 Blown Control 70 -22 Fibers 1 2 3 4 5 6 7 8 9 10 11 12

ALF Testing Rutting Thigh = 64°C Fatigue Tint = 19°C 1 2 3 4 Replicate Fatigue Tint = 28°C

ALF Testing Status (Jan. 05) 1 2 3 4 Lane 5 6 7 8 9 10 11 12 Rutting Test Completed Rutting Test ALF 2 ALF 1 Fatigue Test Shakedown Test Completed Fatigue Test - Initial Strain Measurements: Complete - Rutting Tests: All 12 Lanes Complete - Fatigue Tests: Lanes 1, 2, 4, and 5 Complete - Current Fatigue Tests: Lanes 3 and 6

Rutting Testing Results

HMA Layer Rutting among 100 -mm HMA Pavements

HMA Layer Rutting among 150 -mm HMA Pavements

Lime PG 79

Comparison to Lab Mixture Tests • French Pavement Rutting Tester • Hamburg Wheel Testing Device • Superpave Shear Tester – Repeated Shear at Constant Height (RSCH) – Frequency Sweep (FS) • Simple Performance Tests (under way)

Preliminary Conclusions • Limited Correlation between ALF and mixture lab tests, so far… Best: – 100 mm: French PRT vs. ALF – 150 mm: RSCH vs. ALF • PG 67 -80 Study…

In situ ALF Binders ETG Concern

67 -80 Binders 58 64 70 76 82 88

Fatigue Testing Results

Lane 2 (Control) Lane 4 (SBS LG) Lane 5 (CR-TB) After 100, 000 Loads After 300, 000 Loads After 100, 000 Loads

Future Plan • Complete ALF Fatigue Loading • Conduct Lab Beam Fatigue Tests & SPT • Compare ALF Results to Lab Tests • TWG Meeting in May/June 2005 • Future of APT – with TWG meeting • Continued reporting to the ETG’s

PPA

FHWA Research Problem Statement • Acid modification has been shown to be a low cost way to increase the high temperature stiffness of asphalt binders (per Superpave Binder Specification) but… • Studies have shown both beneficial and harmful effects of acid modification. • • • How should it be used? How should it not be used? What are the pitfalls to avoid?

Proposed Work Plan • Develop forensic method for determining type • and level of phosphate additive Asses durability of acid modification – Effect of environment: light, water, etc. • Address corrosion and handling issues • Optimization of acid modification – Chemical / mechanistic considerations – Different Asphalts – Physical Properties

WARM MIX ASPHALT TECHNOLOGY 44 th Annual Idaho Asphalt Conference October 21, 2004 Moscow, Idaho

Research Needs • A cooperative agreement between FHWA and NCAT is being developed to investigate the performance of three WMA products – WAM-Foam®, Aspha-Min®, Sasobit® (Sasoflex®) – Funding assistance provided by FHWA and through matching funds provided by the product companies • Testing & Evaluation will be conducted at NCAT – – – Compaction at various temperatures Strengthening of the mixes with time Simple performance test, dynamic modulus and moisture sensitivity, etc.

Research Needs • Compatibility with US? – Mix designs – Equipment – Climate conditions – Work practices • Success in Europe = Success in US?

Research Needs • Investigation into – Long term performance – Cost benefits – Plant operations • Definite reduction in fuel, fumes, emissions? – Control of mixing process – Workability at the paving site – Quick turnover to traffic

Moisture

Epoxy Asphalt

That’s all…for now • Thank you