Simple Performance Tests for HotMix Asphalt Concrete

1
Simple Performance TestsforHot-Mix Asphalt
Concrete

• Ramon Bonaquist, P.E.
• Chief Operating Officer
• Advanced Asphalt Technologies, LLC

Simple Performance Test
2
What Is It?

• Test That Indicates How Mix Will Perform
• Rutting
• Cracking

1. Identify Inferior Mixes 2. QC/QA
Operations 3. Structural Design
3
Lots of Possibilities

• Gyratory Compactor
• Rut Testers
• Asphalt Pavement Analyzer
• Hamburg
• Fundamental Tests
• Uniaxial/Triaxial
• Shear
• Indirect Tensile

• Many Show Promising Correlation With Pavement
  Performance Using Limited Data Sets

4
NCHRP/FHWA Research

• To Recommend a Fundamental Based but Simple
  Performance Test(s) to Support of the Superpave
  Volumetric Mix Design Procedure
• Started 1997 FHWA Leadership
• Moved to NCHRP in Late 1998
• Continue Through Early 2003

5
Simple Performance Test Requirements

• Absolute Requirements of Test
• Compliment Superpave Volumetric Design
• Use Gyratory Compacted Specimens
• High Correlation to Rutting/Fracture
• Identify Inferior Mixes
• Preferred Requirements of Test
• Tied to Structural Design
• Adaptable to QC/QA

6
Two Major Projects

• NCHRP Project 9-19
• Recommend Test(s)
• Develop Protocol(s)
• Develop Criteria
• Validate Criteria

• NCHRP Project 9-29
• Equipment Specs
• Procure First Articles
• Evaluate First Articles
• Revise Specs

7
Recommend Tests

• Identify Existing Test Methods
• Correlation Study
• Relate Test Parameters to Observed Performance
• Well Documented Experimental Sections

8
Sites for Correlation Study
MnRoad
WesTrack
FHWA-ALF
9
(No Transcript)
10
Recommend Tests

• Identify Existing Test Methods
• Correlation Study
• Relate Test Parameters to Observed Performance
• Well Documented Experimental Sections
• Select Candidate Tests

11
Candidate Tests

• Dynamic Modulus
• Rutting
• Cracking
• Creep Test
• Rutting
• Repeated Load Test
• Rutting

12
Dynamic Modulus Test

• Rutting
• Min E at High Temp
• Fatigue Cracking
• Max E at Intermediate Temp

13
Creep Flow Time Test

• Rutting
• Min FT at High Temp

14
Repeated Load Permanent Deformation Test

• Rutting
• Min FN at High Temp

15
Advantages

• Dynamic Modulus
• Used For Structural Design in 2002 Design Guide
• Addresses Rutting and Cracking
• Optimization
• Creep
• Simple Test Equipment
• Minimal Training
• Repeated Load
• Potentially Best Simulation of Actual Loading

16
Disadvantage

• Specimen Size
• 100 mm Diameter by 150 mm High
• Smooth Parallel Ends (Sawed)
• Sawed and Cored From Over-Height Gyratory
  Specimens
• Some SGC Can Not Produce Tall Specimens
• Needed to Ensure Fundamental Properties

17
Project 9-19 Criteria Development

• Use Models Proposed in Project 1-37A for the 2002
  AASHTO Design Guide
• Account for
• Climate
• Traffic Level
• Structure
• Test at Effective Pavement Temperature
• Minimum or Maximum Values
• Traffic Level
• Pavement Structure
• Completed in Fall 2002

18
Project 9-19 Validation

• Criteria Will Be Validated
• Not the tests
• In-Service Pavement Data
• 50 LTPP and Other Test Sections
• Completed by the End of 2002

Fatigue Cracking
Rutting
19
Equipment Specifications

• Automated Specimen Fabrication Equipment
• Creep / Flow Time Test
• Repeated Load / Flow Number Test
• Dynamic Modulus Test

20
Specification Development
Draft Equipment Specs Cost Estimate
21
First Article Simple Performance Test System

• EnduraTec
• Instron
• Interlaken
• Shedworks

22
Project 9-29 First Article Simple Performance
Test Systems

• Tests
• Flow Time
• Flow Number
• Dynamic Modulus
• Temperature Range
• 20 to 60 C
• Confining Pressure Range
• 0 to 210 kPa

23
Project 9-29 First Article Simple Performance
Test Systems
INTERLAKEN
SHEDWORKS
24
Project 9-29 First Article Simple Performance
Test Systems
25
Shedworks
26
Shedworks
27
Shedworks
28
Shedworks
29
Interlaken
30
Interlaken
31
Project 9-29 First Article Specimen Fabrication
System

• Pine
• Shedworks

32
Project 9-29 First Article Specimen Fabrication
Equipment
BLADES
CHUCK
CORE BARREL
33
Summary- Simple Performance Test Work Completed

• Three Candidate Tests
• Dynamic Modulus
• Flow Number
• Flow Time
• Detailed Draft Protocols
• Detailed Equipment Specifications
• First Article Devices
• Simple Performance Test System (25 k to 45 k)
• Automated Specimen Fabrication System (12 k)

34
Summary - Simple Performance Test Work in Progress

• Criteria Development
• November, 2002
• Criteria Validation
• End of 2002
• First Article Evaluation
• Early 2003

35
Questions ?
Simple Performance Test