: Tools

Facts regarding LTPPBind 3.0/3.1:

• High-temperature binder selection based on a damage concept is introduced.
• A procedure was introduced to determine PG binders based on rutting damage.
• A transfer function was developed to estimate damage based PG using daily climatic factors.
• An enhanced high-temperature transfer function for pavement temperatures was developed through a comprehensive application of the Integrated Climatic Model (ICM). This model was developed using hourly climatic data, providing a more accurate representation of the high-temperature conditions in the pavement.
• A performance-based procedure utilizing current empirical models for HMA stiffness and rut predictions was developed.
• A damage factor of 1.0 indicating the binder, which should be selected for the current temperature regime.This procedure accounts for extended hot periods in certain climates, which could not be considered in the original selection procedure.
• Models were developed to extend the PG damage concept from the limited number of stations with hourly temperature data to the entire database using daily temperature data.
• A Degree-Days concept was developed to relate the number of days the pavement temperature is over 10 C to the PG damage calculation.
• Comparisons between the original SHRP PG grades and the PG damage based grades were made.
• Also added was the ability to select the acceptable threshold rut level.
• A rational grade bumping procedure was developed based on models for increased traffic and variable traffic speeds.
• The models used for performance were not developed as part of this work but the ones developed in the new M&E design guide.

Download LTPPBind 3.1

LTPPBind is a Windows-based software program developed by LTPP to help highway agencies select the most suitable and cost-effective Superpave asphalt binder Performance Grade (PG) for a particular site. Based on the original binder selection software SHRPBind, LTPPBind features a database of high and low air temperatures (minimum, mean, maximum, standard deviation, and number of years) for U.S. and Canadian weather stations, along with several modifications that provide users with the ability to:

• Select PGs based on actual temperature conditions at their site and at the level of risk designated by their highway agency.
• Use either the original SHRP or LTPP's revised temperature models for determining a site's binder PG.
• Adjust PG selection for different levels of traffic loading and speed.

LTPP's revised temperature models that form the basis for LTPPBind were developed via an LTPP data analysis project. The research report from the project is entitled, LTPP Seasonal Asphalt Concrete Pavement Temperature Models (FHWA-RD-97-103). Two additional SHRP reports contributed to the development of LTPP Bind ver. 2.1. These reports are available for download on the TRB website. SHRP-A-637 - Analysis of Integrated Model of Climatic Effects on Pavement and SHRP-A-648A - Weather Database for the Superpave Mix Design System.

Download LTPPBind 2.1