New Computer Program Helps Highway Engineers Predict and Prevent Pavement Cracking

Federal Highway Administration
January 12, 2000

FOR IMMEDIATE RELEASE
Wednesday, January 12, 2000
Contact: Karen Whitney
Tel.: 202-366-0660
FHWA 3-00

Researchers at the Federal Highway Administration’s Turner-Fairbank Highway Research Center, in concert with industry researchers, have developed a software package that will help engineers construct longer-lasting crack-free pavements. The system will provide a more accurate prediction of the potential for cracking in concrete pavements and overlays during construction.

The High Performance Paving system, or HIPERPAV, is a comprehensive computer model that determines the amount of stress and strength that will develop in portland cement concrete during the early stages of construction.

"This system thoroughly evaluates the factors that make each project unique, enabling engineers to fine-tune each job and eliminate potential problems before construction starts," FHWA Administrator Kenneth R. Wykle said. "It will help take some of the guesswork out of the construction process, saving time and money and yielding a far better product."

Job-specific combinations of mix design, pavement design, construction procedures and environmental factors are entered into the HIPERPAV system and evaluated for their potential to produce cracking. If the potential is found, changes in one or more of the job elements can be tried in subsequent runs of the program until an acceptable combination is found.

Many factors, such as moisture and temperature changes, affect the stress and strength development of pavements. These factors can be particularly damaging during the first 72 hours of construction when concrete is relatively weak compared to the strength it will eventually develop. Critical stresses can develop during this early stage, leading to cracking, and subsequent pavement roughness and poor performance.

Prior to HIPERPAV, pavement predictive models did not account for the complex interactions between the numerous elements involved in each specific project, resulting in generic or inaccurate predictions of performance.

A final report on HIPERPAV, along with the computer software and user’s manual will be available later this month.