Recommendations on Building a Pavement Layer Database for TxDOT (0-1779-1)

An accurate reliable pavement layer database (PLDB) is viewed as essential for the development of improved network and project-level pavement management applications within TxDOT. Very little layer thickness data is available within TxDOT's Pavement Management Information System. This severely impacts its capability to predict future performance and network funding requirements. In the districts, pavement layer information such as the surfacing thickness and the date of last surfacing is needed to assist with pavement rehabilitation decisions. For example, to interpret Falling Weight Deflectometer data, accurate layer thicknesses are required. While some of this data can be obtained from plans, the accuracy of plan thicknesses is often inadequate.|In recent years TxDOT has initiated several internal efforts to establish a pavement layer database. Two districts, Houston and Brownwood, have already stored plan thickness information on a large portion of their networks. In this one-year feasibility study an evaluation is made of the accuracy of the existing databases in these districts, together with an assessment of capability of using Ground Penetrating Radar (GPR) in the validation process. It was found that the plan sheets normally provide the adequate base information (although a few errors were found); however, they do not, in general, provide accurate information on the top layer thicknesses. It is concluded that the current system of using the existing plan sheets to generate the basic database is adequate, but this system must be updated with thickness information from both GPR and coring surveys. The GPR system has the additional benefit of being able to identify defects within the pavement structure. Once established, PLDB updates must become a routine operation upon any project's completion.|Recommendations include action items for both short-term and long-term PLDB development.