HMA dynamic modulus - temperature relations

Garcia, Gabriel; Thompson, Marshall

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https://hdl.handle.net/2142/45996 Copy

Description

Title

HMA dynamic modulus - temperature relations

Author(s)

• Garcia, Gabriel
• Thompson, Marshall

Issue Date

2007-04

Keyword(s)

HMA modulus, hot mix asphalt, HMA modulus- temperature relations

Abstract

A three-stage study to evaluate Hot Mix Asphalt (HMA) dynamic modulus (E*) predictive models using typical Illinois Department of Transportation (IDOT) mixtures and binders was conducted with the objective to propose HMA modulus-temperature generic relations for pavement design applications. Three E* predictive models were evaluated: the current Witczak model (using different ways to obtain the regression intercept (A) and slope (VTS) of the viscosity temperature susceptibility equation), the new Witczak model, and the Hirsch model. The most promising model was the Hirsch model. This model showed the highest precision and the lowest bias. However in general, the model “under predicted” the E*. Based on the bias found applying the Hirsch model, a set of “Correction Factors” (CF) was determined. After applying the CFs to each group of mixtures, the E* predicted with the Hirsch model showed no appreciable bias. Based on some generic volumetric properties for typical Illinois mixtures and binder G* relations for five Illinois binders, a set of “E*-Temperature generic curves” was developed for five different groups of mixtures, applying the Hirsch model corrected for bias. The generic curves (GCs) for each group of mixtures were compared with the E*-Temperature relations used in the current IDOT full-depth HMA pavement design procedure. In general, the GCs predict much higher HMA E* values for a given temperature and mixture than the current IDOT curves. To verify the applicability of the proposed GCs, five mixtures utilized in the Extended Life HMA Pavement (ELHMAP) project at The Advanced Transportation Research & Engineering Lab (ATREL) were compared against the corresponding GC. The results of this comparison were favorable for 12.5-mm and 19.0-mm mixtures using PG 64-22 and PG 70-22. The result for 12.5-mm SMA using PG 76-28 was not favorable. The proposed GCs are considered reasonable first order estimates of HMA E* for routine pavement design purposes for the mixtures in this study, with the exception of 12.5-mm SMA mixtures.

Series/Report Name or Number

FHWA-ICT-07-006

ISSN

0197-9191

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/45996

Sponsor(s)/Grant Number(s)

Illinois Department of Transportation ICT-R39

Copyright and License Information

No restrictions. This document is available to the public through the National Technical Information Service, Springfield, Virginia 22161

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