PowerPoint Presentation - Asphalt Binder Cracking Device (ABCD)
Slide 1
Project Team: EZ Asphalt Technology, LLC, PRI Asphalt Technologies
Award: $239,386
![ABCD ring in silicone mold](images/RingMold2_opt.jpg)
ABCD ring in silicone mold
![Low temperature thermal cracking](images/abcd_low_opt.jpg)
Low temperature thermal cracking
Slide 2 – What Is It?
- ABCD is a test fixture that induces thermal stresses in asphalt binder up to the point of fracture
- Unlike the current standard test, the ABCD test simulates cracking in the field
Slide 3 – Need
- Low temperature thermal cracking (contraction of the pavement) is a major type of asphalt pavement failure
- Nationally, tens of billion dollars are spent to fix cracked pavements every year
![Low temperature thermal cracking in pavement.](images/3.jpg)
Anticipated Advantages:
- A more practical and meaningful laboratory test than the current industry standard specification
- Simpler procedure developed
- Less equipment needed
- Closer approximation to field conditions
- Very promising and supported with data from exploration under the NCHRP IDEA program
Slide 4 – How Does the Test Work?
![ABCD ring in a silicon mold.](images/test.jpg)
A ring of metal with very low thermal contraction is instrumented to measure temperature and strain
![Asphalt binder being tested with the ABCD in the environmental chamber.](images/InChamber2_opt.jpg)
Asphalt binder is poured around the ring then cooled to very low temperatures in a controlled manner
Slide 5 – Cracked specimens collected from the ABCD test
![Cracked specimens collected from the ABCD test.](images/CrackedSpecimen2_opt.jpg)
Cracked specimens collected from the ABCD test.
![Cracked specimens collected from the ABCD test.](images/Picture1_opt.jpg)
The asphalt binder contracts more than the metal restricting the binder, which induces tensile stresses.
![Computerized screen shot of a real-time plot of the ABCD test.](images/binder.jpg)
The asphalt binder fractures, and the temperature of fracture is registered in a computer data acquisition system.
Magnified area: Specimen strain jump due to cracking.
Slide 6 – Planned Refinements
![Free piston sterling cooler.](images/piston.jpg)
Free Piston Sterling Cooler
VS.
![Conventional environmental chamber.](images/chamber.jpg)
Conventional Environmental Chamber
- Simplifications to both the software and the hardware
- Replaces the need for a large temperature cooling chamber
- Lightweight
- Operator friendly
- Smaller in size
- Little to no moving parts
- Automatic data processing and analysis after test completed