NAPAUpdate

Virtual Superpave LaboratoryVirtual Superpave Laboratory

Introduction to Superpave

Aggregate Tests • Binder Tests • Mix Design • Performance Tests

How To Use the Virtual Superpave Laboratory • Product Directory

Credits • Copyright Notice •

http://www.pineinst.com/Default.htm

Home | Introduction | Aggregate Tests | Binder Tests | Mix Design | Performance Tests | Product Directory

Binder Tests – Main Menu

1. .Introduction

2. Aging Tests• Rolling Thin Film Oven Test (RTFO)

• Pressure Aging Vessel (PAV)

3 Rheological Tests

• Rotational Viscometer (RV)

• Dynamic Shear Rheometer (DSR)

• Bending Beam Rheometer (BBR)

• Direct Tension Tester (DTT)

4 Binder Tests Quiz

Dynamic Shear RheometerOverview • Discussion • Perform Test •Results

The dynamic shear rheometer (DSR) is used for testing medium to high temperature viscosities (the test is conducted between 46° C (115° F) and 82° C (180° F)). The actual temperatures anticipated in the area where the asphalt binder will be placed determine the test temperatures used.

The basic DSR test uses a thin asphalt binder sample sandwiched between two plates. The lower plate is fixed while the upper plate oscillates back and forth across the sample at 1.59 Hz to create a shearing action (view animation).

Asphalt binders in the medium to high temperature range behave partly like an elastic solid (deformation due to loading is recoverable – it is able to return to its original shape after a load is removed) and a viscous liquid (deformation due to loading is non-recoverable – it cannot return to its original shape after a load is removed). The DSR measures a complex shear modulus (G*) and a phase angle (d), which is the time lag, expressed in radians, between the maximum applied shear stress and the maximum resulting shear strain. Using these measurements, the DSR is able to determine the elastic and viscous components of G* (see Fig re belo )

DSR at NCAT

Home | Introduction | Aggregate Tests | Binder Tests | Mix Design | Performance Tests | Product Directory

DSR at the Washington State DOT Materials Laboratory

Why is VSL needed?• Technology has changed

– More tests– More complexity

• Teaching Institutions have fewer $’s– Reduced funding– Reduced staff

• Expertise is decreasing– Early retirements– Fewer technicians and engineers

How will VSL be used?

• Supplement hands-on training– Student completes modules before

performing tests– Saves time and frustration– Data collection and analysis easily

referenced• Stand-alone, self-directed learning

Who will use the VSL?• Universities• Community Colleges/Vo-Techs• Technician Training Courses• Individuals• Who will it reach?

– Contractors– Agencies– Consultants

How will VSL be created?• University of Washington and NCAT

– UW provides technology and content– NCAT provides content

• Funding– Laboratory Equipment Manufacturers – Associate Members Council Fund

Raising– NAPA

• Time Frame: 18 to 24 months

Porous Asphalt Pavement----

An Overview

What WeUsually Do.

Pavement

Storm Sewer Inlet

Storm Sewer Inlet

What WeUsually Do.

DrainageField

DetentionPond

An Alternative

Advantages• Reduced surface runoff• Better erosion control• Better water quality• Reduced storm sewer requirements• Maintain natural drainage paths• Reduced standing water nuisance• Better GWT recharge• Better skid resistance

University of North CarolinaChapel Hill

Friday Center Park & Ride

• University - City Agreement - No increase in GW pollution

• 800 vehicle lot• $2500/stall vs $3000/stall conventional

Placement of Fabric

UNC Parking Lot

Paving Operation

UNC Parking Lot

Drainage Demonstration

UNC Parking Lot

Finished Parking Lot

UNC Parking Lot

Vehicle Loading

• Best for:– Parking lots– Recreational areas– Sports complexes

• High volume automobile traffic or truck traffic - Consider using Asphalt Treated Permeable Base

Conclusions

• Numerous Advantages to Porous Asphalt Pavements

• Examples of Successful Facilities• Need Flat Site with Permeable Soils

and Low GWT• Need Low Traffic• Attention to Detail in Construction• Maintenance is Important

PerRoadPerpetual Pavement

Design Guide

Dave TimmNational Center for Asphalt

TechnologyAuburn University

› Fatigue Resistant Asphalt Base

» Minimize Tensile Strain with Pavement Thickness» Thicker Asphalt Pavement = Lower Strain» Strain Below Fatigue Limit = Indefinite Life

CompressiveStrain

Strain

Fatigue Life

IndefiniteFatigue

Life

Tensile Strain

4000

5000

6000

7000

8000

0.0E+00 5.0E+06 1.0E+07 1.5E+07 2.0E+07 2.5E+07 3.0E+07 3.5E+07 4.0E+07

Number of Load Cycles

Stiff

ness

, Mpa

70 Micro Strain TestUniversity of Illinois

Failure @ Stiffness < 50%

Monte Carlo Simulation

WESLEA

x1 x2

f f

N

f

Input Distributions

Output DistributionProbability of Exceeding Threshold

Pavement Type SelectionProcess

- A Position Paper -

States Changing PTS

• Ohio• Maryland• Minnesota• Washington• South Carolina

Purpose

• Provide agencies with a united industry position.

• Explain advantages of asphalt according to AASHTO PTS guideline.

• Position industry on side of taxpayers.• Provide guidance on critical issues.

Organization• Summary

– Do what’s right for the taxpayers.– PTS should be:

• Objective• Defensible• Understandable• Based on facts• Driven by economics• Periodically reviewed

– Asphalt pavements should always be considered.

Other NAPA Stuff

• Best Practices Manual• Revision of Research Priorities• Reauthorization• Superpave Workshops• Dance Contests

I’m lookin’ good!

What an ASS!

NAPAUpdateVirtual Superpave LaboratoryWhy is VSL needed?How will VSL be used?Who will use the VSL?How will VSL be created?Porous Asphalt Pavement----An OverviewAdvantagesUniversity of North CarolinaChapel HillFriday Center Park & RidePlacement of FabricPaving OperationDrainage DemonstrationFinished Parking LotVehicle LoadingConclusionsPerRoadPerpetual PavementDesign GuidePavement Type SelectionProcess- A Position Paper -States Changing PTSPurposeOrganizationOther NAPA Stuff