2013 Session: 500

• Statistical Determination of Agricultural Vehicle-Induced Bridge Distribution Factor Threshold
  Abstract: Most studies to date on live-load distribution factor (DF) determination have focused on the examination of bridges under normal highway-type vehicles. Many bridges are in use on rural roadways where agricultural vehicle travel is common and therefore the impacts of their atypical load types should be explicitly considered. Developing systematic methodologies accounting for their effects are also critical for more reasonable safety assessment of rural bridges. The primary objective of this study is to develop a statistical framework to determine DFs for rural bridges subjected to agricultural vehicles. A sample bridge in a rural area of Iowa was selected for demonstration of the proposed statistical framework. The proposed procedure consists of multiple parts including live load field testing, finite element simulations, and statistical analyses. A network of multiple strain sensors were installed at the critical locations on the bridge to monitor strain time histories resulting from passes of farm vehicles with known characteristics. Strains were utilized to compute field measured DFs and also used to calibrate analytical models. As part of the model simulation, farm vehicles commonly found in the United States were chosen and applied to the model to calculate their DFs. Statistical thresholds for the exterior and interior girders were calculated by performing a statistical analysis of the computed data. The thresholds were compared to the AASHTO code-specified DFs (for both the Standard Specification and the LRFD Specification), indicating the interior girder limit was below yet the exterior limit was above the AASHTO values.
  Authors: Seo, Junwon; Phares, Brent Matthew; Dahlberg, Justin; Wipf, Terry J.; Abu-Hawash, Ahmad
  Authors: Seo, Junwon; Phares, Brent Matthew; Dahlberg, Justin; Wipf, Terry J.; Abu-Hawash, Ahmad
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Maintenance and Preservation
  Session: 500
  Paper Number: 13-0633
• Bridge Deck Scanning for Condition Assessment of Bare Concrete and Asphalt-Overlaid Decks
  Abstract: This paper presents technologies used for condition assessment of bare concrete decks and asphalt overlaid decks. The study was funded by the NCHRP-IDEA program. The objective of the research and development was to develop a faster, more accurate technology to determine internal conditions of bridge decks. A Bridge Deck Scanner (BDS) prototype with a pair of transducer wheels was originally developed. Later the BDS system was expanded as part of a SHRP 2 R06 (D) research project for asphalt pavement delamination (NCAT study at Auburn University) so that up to three pairs of transducer wheels could be added to the system for more rapid testing. The BDS system can be set to perform either Impact Echo Scanning on all wheels for condition assessment of bare concrete decks or simultaneously perform Impact Echo Scanning and Spectral Analysis of Surface Waves Scanning for condition assessment of concrete decks underneath overlays such as asphalt. In this paper, two case studies are presented (one from a bare concrete deck and one from an asphalt overlaid deck) in which comparison/ground-truthing techniques (sounding, coring, hydro-blasting, etc.) were employed along with BDS results.
  Authors: Tinkey, Yajai; Miller, Patrick K.; Leonard, Mark; Pott, Andy; Olson, Larry Duane
  Authors: Tinkey, Yajai; Miller, Patrick K.; Leonard, Mark; Pott, Andy; Olson, Larry Duane
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Maintenance and Preservation
  Session: 500
  Paper Number: 13-2043
• Application of Impact Echo Scanning for Void Detection on Concrete Test Beams That Replicate Different Surface Finishes
  Abstract: The purpose of this study is to investigate the application of the hand-held impact echo scanning system for void detection in concrete structures. Three beams were designed to represent various surface and void conditions including different surface finishes (smooth, broom, and tined), overlays (rapid set, latex, and polymer), and rebar location. Impact echo (IE) testing was performed using the hand-held IE scanner system, which automatically performs an IE test every 1 in (25 mm). The scans were performed perpendicular to the direction of the foam voids. Comparisons of the defect interpretations and the actual design conditions of the beams are presented. It was concluded that while the hand-held IE scanner performed well in applications with relatively smooth surface, it has difficulty with applications with rough surfaces. The rough polymer, tined, and broomed surfaces caused poor quality data. However, the hand-held IE scanner was still able to detect shallow delaminations even from structures with rough surfaces. The scanner’s small size and weight make it ideal for testing smooth surfaces where testing is more difficult, such as vertical or overhead surfaces.
  Authors: Lewis, Kevin G.; Sharp, Stephen R.
  Authors: Lewis, Kevin G.; Sharp, Stephen R.
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Maintenance and Preservation
  Session: 500
  Paper Number: 13-2832
• Streicker Bridge in Its Early Years: Structural Identification and Damage Characterization
  Abstract: Streicker Bridge on the Princeton University Campus is a new pedestrian bridge completed in 2010. It is equipped with a Structural Health Monitoring (SHM) system aimed to transform the bridge into an on-site laboratory for research and educational purposes. Its very slender elements, modern materials and daring geometry create a structurally complex system. This on-site laboratory gives an opportunity not only to assess the structural behavior of this particular bridge but also to gain experience, research and develop sensing technologies, as well as to develop and validate data analysis techniques for damage detection and structural identification. Two fiber-optic sensing technologies are currently permanently deployed: discrete long-gage sensing based on Fiber Bragg-Gratings (FBG) and truly distributed sensing based on Brillouin Optical Time Domain Analysis (BOTDA). The sensors were embedded in the concrete deck during the construction. Several static and dynamic load tests were made and combined with major events such as the removal of the formwork to perform structural identification and damage characterization. An overview of the structural identification of the bridge performed at an early stage of its life is presented in this paper. It includes a description of the monitoring system, the applied monitoring strategies and in particular the global static behavior, characterization of a damaged joint, dynamic behavior and thermal effects. The results show that the selected monitoring strategy was suitable for monitoring this complex bridge, and that the selected monitoring system was able to capture the main features related to the real structural behaviors of the bridge.
  Authors: Sigurdardottir, Dorotea Hoeg; Glisic, Branko; Afonso, Jose Pedro Sousa
  Authors: Sigurdardottir, Dorotea Hoeg; Glisic, Branko; Afonso, Jose Pedro Sousa
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Maintenance and Preservation
  Session: 500
  Paper Number: 13-2714
• Patch Analysis of Reinforced-Concrete Bridge Decks Using Ground-Penetrating Radar
  Abstract: The common practice of patching decayed or damaged bridge decks introduces unique challenges to non-destructive testing (NDT) techniques when the deck is extensively patched. NDT techniques are useful to gain knowledge of damaged bridge decks, but it is important to know their limitations to correctly assess the condition and remaining life of the structure. Three bridge decks in the New England area were subjected to a suit of testing which included ground penetrating radar, half cell potential, chain drag/hammer sounding, visual inspection and core sampling. Two of the three decks had large patched areas. The data from each of the tests, specifically ground penetrating radar and half-cell potentials, allow for the comparison and the identification of the limitations of each individual test. Using the gained knowledge of the shortcomings of individual tests, it allows the data interpreter to identify ways to compensate for the unique difficulties caused by patched bridge decks. With a better understanding of the data collected from NDTs, higher precision QC/QA can be performed, which can lead to increased savings and higher durability of the bridge decks.
  Authors: Martino, Nicole; Vilbig, Reid; Birken, Ralf; Maser, Kenneth R.
  Authors: Martino, Nicole; Vilbig, Reid; Birken, Ralf; Maser, Kenneth R.
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design; Maintenance and Preservation
  Session: 500
  Paper Number: 13-3242
• Streicker Bridge in Its Early Years: Structural Identification and Damage Characterization
  Authors: Sigurdardottir, Dorotea
  Authors: Sigurdardottir, Dorotea
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Bridges and Other Structures; Design; Maintenance and Preservation
  Session: 500
  Paper Number: 13-2714
• Patch Analysis of Reinforced-Concrete Bridge Decks Using Ground-Penetrating Radar
  Authors: Martino, Nicole
  Authors: Martino, Nicole
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Bridges and Other Structures; Design; Maintenance and Preservation
  Session: 500
  Paper Number: 13-3242
• Application of Impact Echo Scanning for Void Detection on Concrete Test Beams That Replicate Different Surface Finishes
  Authors: Sharp, Stephen
  Authors: Sharp, Stephen
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Bridges and Other Structures; Design; Maintenance and Preservation
  Session: 500
  Paper Number: 13-2832