MPC
Research Projects (2003-04)

Identifying Number

MPC-243

Project Title

Assessment of Thermal Stresses in Asphalt Pavements Due to Environmental Conditions Including Freeze and Thaw Cycles

University

University of Wyoming

Project Investigators

Dr. C. Yavuzturk (cyturk@uwyo.edu)
Dr. K. Ksaibati (khaled@uwyo.edu)
University of Wyoming
Civil and Architectural Engineering Dept
Phone: (307)766-6142 & (307)766-6230
Fax: (307)766-2221

External Project Contact

Antonio Nieves Torres
LTPP Field Engineer
National Resource Center - Midwest
Phone: (202)493-3074
Fax: (202)493-3161
antonio.nieves@fhwa.dot.gov12

Project Objective

This is Phase II of a previous MPC research project (MPC Report No. 02-136) that developed a computer model using a transient, two-dimensional finite volume approach to mathematically describe the thermal response of asphalt pavements due to thermal environmental conditions on an hourly basis. The main objective of Phase II research is to expand the capabilities of the computer model to include the thermal effects of precipitation (rain and snow) and to study the impact of the tilt angle from the horizontal of an asphalt pavement asphalt temperature predictions. With the expanded capabilities of the computer model, it will be possible to accurately study and assess thermal stresses in and between various asphalt pavement lifts during seasonal and diurnal freeze/thaw cycles.

Project Abstract

Temperature fluctuations in asphalt pavements significantly affect pavement stability and the selection of asphalt grading. Ability to accurately predict asphalt pavement temperatures at different depths and horizontal locations based on environmental conditions will greatly help pavement engineers not only in the selection of the asphalt grade to be used in various pavement lifts, but also in the accurate assessment of thermal stresses in and between various asphalt lifts. This is especially critical when the asphalt pavement is exposed to extreme freeze and thaw conditions. Accurate knowledge of the temperature and thermal stress distribution in asphalt pavements will allow for a more sophisticated specification of asphalt binder grades for lower lifts and thus provide an economical solution to rising pavement construction costs.

Task Descriptions

• Conduct literature review with focus on freeze/thaw cycles and thermal stresses in asphalt pavements (August 2003).
• Expand current computer model to include the thermal effects of precipitation and pavement tilt angle (November 2003).
• Conduct model validation of the enhanced heat transfer model using LTPP DataPave database (December 2003).
• Conduct sensitivity analyses to assess the impact of asphalt material properties, asphalt geometry and precipitation on asphalt thermal response (February 2003).
• Conduct simulation studies for the prediction of thermal stresses in and between various asphalt lifts. Perform preliminary studies to predict the impact of thermal stresses on failures in and between lifts (May 2003).
• Submit a final report (June 2004).
• Submit a technical paper to the Transportation Research Board meeting and/or other reputable transportation engineering/pavement materials science journals(August 2004).

Milestones, Dates

Starting Date: July 1, 2003
Ending Date: June 30, 2004

Student Involvement

One graduate student

Relationship to Other Research Projects

This is Phase II of a previous MPC research project (MPC Report No. 02-136) that developed a computer model using a transient, two-dimensional finite volume approach to mathematically describe the thermal response of asphalt pavements due to thermal environmental conditions on an hourly basis.

Technology Transfer Activities

Computer model to predict two-dimensional temperature distributions and thermal stresses in asphalt pavements on an hourly basis. The model will greatly aid pavement engineers in assessing the impact of freeze/thaw cycles. Research results will be disseminated through a final report, a technical paper and presentations.

Transportation Departments in Region 8.

Potential Benefits of the Project

Temperature distributions and thermal stresses in asphalt pavements, impact of environmental conditions including freeze and thaw cycles on the thermal response of pavements, prediction of the impact of thermal stresses on asphalt pavement failures in and between lifts.

The results of this research are expected to provide pavement engineers with more accurate assessment tools on temperature and thermal stress distribution in asphalt pavements. Such information will be very beneficial in establishing protocols for back-calculations of pavement modulus values. In addition, the results will help engineers select more cost-effective asphalt materials (PG binders) for various pavement lifts. The results of this study are expected to have an immediate impact on the development of cost-effective design practices.

TRB Keywords

Pavements, asphalt pavements, asphalt mixes, pavement conditions, pavement deflections, heat transfer, finite differences, finite difference method, environmental impacts, temperature distribution, thermal stress