Superpave in 2012 • Intro. – Dick Reaves, North American Sales Manager • History of SHRP/Superpave

• Basics of Superpave

• History of Gyratory Compactors

• The Missing Link – Performance Tests • The Latest Generation of Gyratory Compactors

• The Future

SHRP/Superpave- The History • The Strategic Highway Research Program (SHRP) was

established by Congress in 1987 as a 5 year, $150-million research program to improve the performance and durability of our highway system.

• Increased truck tire pressures and the increased use of radial tires changed the loads on the pavements and rutting problems increased.

SHRP/Superpave – The History • The rutting problems had become so severe that many

pavements were failing well before the end of their projected design life.

• One of the goals of SHRP was to come up with a new mix design method that would account for the loads on the pavement and site specific environmental conditions.

• In 1994, SHRP introduced the Superior Performing Asphalt Pavements (SuperpaveTM) laboratory mix design procedure.

•Superpave was one of many products to come out of SHRP, but it was undoubtedly the one with the most impact on the highway industry.

Superpave • FHWA Targeted Implementation by 2000 • 47 states implemented PG-graded binder specs

by 2001 • Over 50% of total projects and tonnage were

Superpave in 2001 • Estimated 80% of total projects and tonnage

were Superpave in 2011

Superpave • What is a Superpave asphalt mix?

– Asphalt binder that meets performance graded specifications – Aggregate blend that meets Superpave gradations and criteria – Mix designed using the Superpave Gyratory Compactor – New Volumetric Properties Specs – New Moisture Sensitivity Specs

Superpave • 1994- there were 28 different design gyration levels (N

design). • They represented 7 traffic levels for each

of 4 climates. • 1999- consolidated to 4 levels. • Climate regions were eliminated because

binder grade should address this. • Simplified the design process

Gyratory Compactor- History • Original Specifications: Pressure 200 to 1000 KPa; Angle 0.5° to 2.0° ± .02°; 30 gyrations per minute • FHWA solicited manufacturers to build prototypes • Troxler 4140 and big Pine were selected as the two approved

Superpave Gyratory Compactors. • Researchers settled on 600 KPa Pressure and 1.25° external

angle • Both Troxler and Pine developed smaller portable units with set

angle and pressure. (The Troxler 4141 and the small Pine.) • Some others got their products approved. • In early 2000s Dynamic Angle Verifier (DAV) became available.

– Confirmed with 1.25° external angle, internal angle not always the same.

• Set new angle spec of 1.16° internal angle.

DAV II w/HMS • The Dynamic Angle Verifier • Used with Hot Mix or Hot Mix Simulator • Fits in any 150 mm mold • Makes checking and adjusting the angle easier and

more reliable • Developed by Tom Brovold and FHWA

5850 Sales Presentation / Confidential

What is a Gyratory Compactor? • The Superpave Gyratory Compactor (SGC) prepares a HMA

sample using a compaction effort intended to simulate the effects of field compaction. Small samples can be used to test potential mix designs and select the most appropriate one.

• The standard SGC procedure is: AASHTO T 312: Preparing and Determining the Density of Hot-Mix Asphalt (HMA) Specimens by Means of the Superpave Gyratory Compactor

• The basic SGC uses about 10 lbs (4500 to 5000 g) of HMA and compacts it in a mold to produce a sample, typically

6 inches (150 mm) in diameter and 4.5 inches (115 mm) or more tall. A continuous load is applied to the top or bottom of the warm asphalt sample while it is inclined at 1.25° and

rotates at 30 revolutions per minute.

The Missing Link • Superpave is a mix design procedure. • Industry identified need for performance tests. • Developed the “Simple Performance Tester”. • Not simple or totally accepted – Expensive. • Evolved into the “AMPT” or “Asphalt Mix Performance Tester”.

– Need to make taller specimens. (185 mm instead of 115 mm) • Sample prepared by sawing and coring tall gyratory specimen.

– Eliminates “edge-effect”.

Troxler Model 5850 Gyratory Compactor • Meets all Superpave and

FHWA requirements • Improved rigidity over older

models • Troxler’s most portable

gyratory compactor • Fewer moving parts • Shear option available

Model 5850 – Features and Benefits • The 5850 is powered by a hydraulic motor, meaning fewer

moving parts, less opportunity for wear and easier and less expensive service.

• Asphalt Mix Performance Test specimens, as tall as 185mm, are easily produced, allowing users to meet performance test requirements.

• Shear measurement is an option on the Troxler Model 5850. Users may choose the shear option at the time of purchase or add it at a later date.

• The Troxler Model 5850 is so quiet a beeper function was added to indicate that a test is complete!

Model 5850 – Features and Benefits • The easy to use software allows users to program internal or

external angles as requirements change.

• Moving this gyratory to a different lab is simple. The small footprint and reduced weight of the 5850 makes it easy to transport by unlocking the wheels and rolling it to a new location!

• The Model 5850 is designed with safety and ergonomics in mind. Specially designed safety interlock switches keep all doors and panels closed while the machine is producing a sample. The 5850 was designed so that all work is performed by both the unit and the operator at one level. There is no awkward lifting to remove molds or pucks. Simply slide the mold out of the chamber and move onto the separate gravity extruder for easy extraction.

Model 5850 – Simple One Button Operation Operator selects desired

number of gyrations (0-999) or desired compaction height

Easy one button operation: press START and the 5850 will go through the compaction process automatically.

Height data can be downloaded to a printer, thumb drive or a computer via either the serial or USB port

Note: Hot mix asphalt and gyratory molds need to be preheated based on local specifications, typically 140-155C (285-310F).

Model 5850 – Loading the Mold

Place a specimen paper into the mold

Place preheated asphalt mix into the mold

Place the second specimen paper on the top of the mix

Place upper puck in mold

Model 5850 – Compaction Process Place the mold in the compaction chamber and close the door Press “START” 5850 will gyrate to selected number of gyrations or to height Beeper will announce the completion of compaction process

Future • Other performance tests are available or being developed • Two primary modes of failure; Rutting and Cracking • Industry looking at a variety of tests • For Rutting:

– Hamburg Wheel Tester – Asphalt Pavement Analyzer (APA)

• For Cracking: – Overlay Tester – DCT – Bending Beam

APA

Overlay Tester

Wheel Tester

Future

• Shear Testing is being discussed more and more. – A measure of the stiffness of the mix. – Measures resistance during compaction in gyratory

compactor mold. • The Model 5850 has Shear capability as an option. • We also offer the Gyratory Shear Kit (GSK) • Will work with any gyratory compactor that uses a150 mm

mold

Gyratory Shear Kit? • A Gyratory Shear Kit (GSK) is a small device that fits into any gyratory

compactor mold on the market and turns the gyratory compactor into a Shear enabled machine

• By taking three load cell measurements simultaneously, the 1.125” tall GSK monitors the real time internal compaction that the specimen is experiencing • Not only does the GSK make any gyratory compactor shear capable, it will verify shear on a shear enabled gyratory. You may also calibrate total load by using a GSK in conjunction with a RAM or DAVII

• Patent licensed from University of Wisconsin & Dr. Hussain Bahia

In cooperation with the University of Wisconsin

Superpave gyratory Compactor • Thank you. • Questions?

5850 Sales Presentation / Confidential

Model 5850 – Brochure