Evaluate the Fatigue Resistance of Rut Resistance Mixes

Project Description

The Texas Department of Transportation (TxDOT) has long focused research efforts on improving hot mix asphalt concrete (HMAC) mix design to preclude rutting in the early life of pavements. However, these rut-resistant stiff mixtures may be susceptible to long-term fatigue cracking due among other factors to oxidative aging.

This project completed initial development of an HMAC mixture fatigue design and analysis system and associated surrogate fatigue tests to ensure adequate mixture fatigue performance in a particular pavement structure under specific environmental and traffic loading conditions. In addition, the study compared the fatigue resistance of commonly used TxDOT HMAC mixtures and investigated the effects of binder oxidative aging on fatigue performance.

Researchers completed an information search and conducted a survey to gather data on:

• current fatigue design and analysis approaches;
• related laboratory tests, materials, pavement structures, and designs;
• corresponding standards or references; and
• resources or methodologies used to obtain fatigue-resistant HMAC mixtures.

In addition, they conducted comprehensive laboratory tests for binders and HMAC mixtures.

Among their findings, the researchers determined that HMAC mixture fatigue resistance is a complex function of mix design parameters (including binder type/content, air voids), aggregate type/gradation), material properties (binder, aggregate, and HMAC), traffic, pavement structure, and environment. These factors interact in a unique way in each HMAC mixture and should be explicitly taken into account when designing and modeling HMAC mixtures for fatigue resistance.

Project Publications

Comparison of Fatigue Analysis Approaches for Two Hot Mix Asphalt Concrete (HMAC) Mixtures 0-4468-2

Application of Calibrated Mechanistic Fatigue Analysis with Aging Effects 0-4468-3

Preliminary Fatigue Analysis of a Common TxDOT Hot Mix Asphalt Concrete Mixture 0-4468-1

Initial Development of a Calibrated Mechanistic Approach and Associated Surrogate Test Protocols for HMAC Mixture Fatigue Characterization 0-4468-S

Texas Transportation Researcher Articles

Combating pavement cracking - Volume 42, Number 3

For More Information