Creating a better pavement
Updated FHWA software helps identify factors in high-performance concrete pavement
A new software tool available from the Federal Highway Administration (FHWA) is providing transportation agencies and contractors with a helping hand in the design and construction of concrete pavements. HIPERPAV II is an updated and expanded version of FHWA’s original HIPERPAV (HIgh PERformance PAVing) software. The HIPERPAV II system was developed as a tool for predicting the early-age behavior of both jointed plain concrete pavements (JPCP) and continuously reinforced concrete pavements (CRCP). In addition, the software addresses the effect of early-age behavior factors on the long-term performance of JPCP. It is expected that these predictive capabilities will help designers, contractors and concrete suppliers identify factors that can contribute to achieving good-performing pavements. Similarly, it is expected factors that could potentially put the pave-ment’s long-term performance at risk also can be identified.
Planners can use HIPERPAV II to develop quality-control specifications for projects based on the available materials and climatic conditions in the region of construction. For designers, HIPERPAV II may be used to optimize pavement designs so that an improved long-term pavement performance is achieved.
Contractors, meanwhile, can use the software to prevent expensive pavement repairs, estimate approximate set time as a function of materials and climatic conditions and evaluate the effect of using a given concrete mix throughout different seasons, among other applications.
Higher potential for cracking caused by unexpected changes in the weather can be predicted and avoided. Using HIPERPAV II, the effect of these changes on the pavement is quantified and an alternative construction time or method can be identified to reduce or prevent pavement damage. Suppliers also can use the program to assess the performance of a given mix design under various climatic conditions.
Finally, HIPERPAV II may be used as a forensic analysis tool for pavements. For example, engineers can use it to better pinpoint the reasons behind pavement damage or poor pavement performance, allowing them to improve design and construction practices.
Among the states using HIPERPAV II is Ohio, which recently began specifying that the software be used for all portland cement concrete pavement construction.
Enhancements incorporated in HIPERPAV II include the ability to analyze multiple strategies for one project, as well as a new graphical user’s interface that accommodates different analysis types and options while retaining the simplicity and user friendliness of the earlier version of the software.
The improved program also features a reference database, which contains the primary references used during the development of HIPERPAV II.
A geographical weather database system, meanwhile, features historical averages of weather data from weather stations throughout the U.S. Climatic information provided includes air temperature, wind speed, relative humidity, cloudiness and annual rainfall conditions.
A three-volume accompanying documentation series, Computer-Based Guidelines for Concrete Pavements, provides details on the development of the software. Volume I (Publication No. FHWA-HRT-04-121) provides a project summary, while Volume II (Publication No. FHWA-HRT-04-122) presents the HIPERPAV II user’s manual. The technical appendixes documenting the investigation, modeling and validation of the software are contained in Volume III (Publication No. FHWA-04-127).
The HIPERPAV II software and Volumes I and II of the guidelines are available online (www.fhwa.dot.gov/pavement/pccp/hipemain.cfm). Volume III will be posted online shortly. Also available on the website is a list of frequently asked questions about using the software.
These questions cover such topics as the design, environmental and construction inputs; the software interface; and data analysis.