Uncoated weathering steel bridge data collection and performance assessment: bridge maintenance practices, deicing agent use, and field sampling
Date
2020
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
The long-term performance of uncoated weathering steel (UWS) bridges in the United States is being assessed to update the current FHWA technical advisory regarding the use of UWS in highway bridges. The main purpose of the larger research project, to which the research described in this thesis contributed, is to develop quantitative recommendations about environmental conditions and maintenance practices that may be the most suitable for UWS highway bridges. Prior work included the development of a national UWS GIS database in order to quantify environments. This database was used to strategically select 21 UWS bridges for field evaluations in 7 states in order to qualitatively assess the performance of rust patinas and collect rust samples for assessment using quantifiable metrics. Rust samples were assessed by evaluating data from clear tape adhesion tests and ion chromatography analyses. Part of this research also included collecting and analyzing maintenance data collected from state highway agencies throughout the United States. This data included information from 34 state highway agencies’ bridge maintenance manuals and bridge washing practices from 33 state highway agencies. Deicing agent usage data was also obtained from 39 state highway agencies and existing databases. Correlations between the different data types that were collected were assessed to investigate any trends in UWS bridge performance based on environmental conditions and maintenance practices. The most significant finding from this research involved differences in UWS performance as quantified by chloride concentrations and rust particle sizes of surface rust based on interior, sheltered girder locations and exterior, exposed girder locations. Quantifiable data obtained from this research will be useful for evaluating UWS bridge performance trends with a larger dataset in order to update national specifications and maintenance practices involving UWS bridges.
Description
Keywords
Bridge, Performance assessment, Steel, Uncoated, Weathering