Assessment of Aging at FHWA's Pavement Testing Facility

Abstract

Field cores were taken in 1995 and 2002 from eight asphalt pavements constructed in 1993 at FHWA's pavement testing facility to evaluate in situ pavement aging. Dynamic mechanical properties of these cores were evaluated by using the Superpave® shear tester. The moduli of aged pavements were also predicted from binder, aggregate, and mixture properties with available prediction models, and the aging severity levels of all pavements were compared between the lab-measured and model-predicted. Eight pavements with two polymer-modified and six unmodified binders were evaluated in this study. Polymer-modified asphalt pavements showed comparatively lower aging than unmodified asphalt pavements. For unmodified asphalt pavements, stiffer asphalts tended to have higher aging indices. The binder aging index was found to be inversely proportional to the loading frequency, and differences between the aging indices for different binders were higher at lower frequency. Comparison of lab-measured and model-predicted binder aging indices showed similar rankings for all binders. Low stiffness binders, for example, AC-5, showed higher aging indices than high stiffness binders, for example, Styrelf. Pavement depth significantly affected binder aging. The aging index near the surface (6.35 mm) was found to be about four to five times the aging index at a depth of 139.7 mm in pavement. Comparison of lab-measured and model-predicted mixture aging indices showed large variations, from overpredicted to quite underpredicted, depending on the binder type and nominal maximum aggregate size.

Get full access to this article

View all access options for this article.

References

Krchma

L. C.

, and Gagle

D. W.

. A USA History of Asphalt Refined from Crude Oil and Its Distribution. Journal of the Association of Asphalt Paving Technologists, Vol. 43A, 1974, pp. 26–88.

Chiu

-T, Tia

, Ruth

B. E.

, and Page

G. C.

. Investigation of Laboratory Aging Processes of Asphalt Binders Used in Florida. In Transportation Research Record 1436, TRB, National Research Council, Washington, D.C., 1994, pp. 60–70.

Bell

C. A.

SHRP-A/IR-89-004: Summary Report on Aging of Asphalt-Aggregate Systems. TRB, National Research Council, Washington, D.C., 1989.

Oliver

J. W. H.

, and Tredrea

P. F.

. The Change in Properties of Polymer Modified Binders with Simulated Field Exposure. Journal of the Association of Asphalt Paving Technologists, Vol. 66, 1997, pp. 570–602.

Petersen

J. C.

Chemical Composition of Asphalt as Related to Asphalt Durability: State of the Art. In Transportation Research Record 999, TRB, National Research Council, Washington, D.C., 1984, pp. 13–30.

Traxler

R. N.

Relation Between Asphalt Composition and Hardening by Volatilization and Oxidation.

Journal of the Association of Asphalt Paving Technologists, Vol. 30, 1961, pp. 359–377.

Tayebali

A. A.

, Tsai

, and Monismith

C. L.

. SHRP-A-388: Stiffness of Asphalt-Aggregate Mixes. TRB, National Research Council, Washington, D.C., 1994.

Mirza

M. W.

, and Witczak

M. W.

. Development of a Global Aging System for Short and Long Term Aging of Asphalt Cements. Journal of the Association of Asphalt Paving Technologists, Vol. 64, 1995, pp. 393–430.

Fonseca

O. A.

, and Witczak

M. W.

. A Prediction Methodology for the Dynamic Modulus of In-Place Aged Asphalt Mixtures. Journal of the Association of Asphalt Paving Technologists, Vol. 65, 1996, pp. 532–572.

10.

Pellinen

, and Killingsworth

. ALF Pavement Core Testing, TWR TC01-510, Permanent Deformation Predictions Using Superpave Software. FHWA, U.S. Department of Transportation, 1996.

11.

Witczak

M. W.

, and Pellinen

T. K.

. NCHRP 9-19: AC Mixture Response Comparison to Performance E* and S_m Prediction Equation Methodology Results. TRB, National Research Council, Washington, D.C., 2000.

12.

Huang

Y. H.

Dynamic Modulus of Bituminous Mixtures. In Pavement Analysis and Design, Prentice Hall, Englewood Cliffs, N.J., 1993, pp. 334–347.

13.

Zeng

, Bahia

, Zhai

, Anderson

M. R.

, and Turner

. Rheological Modeling of Modified Asphalt Binders and Mixtures. Journal of the Association of Asphalt Paving Technologists, Vol. 70, 2001, pp. 403–441.