Nondestructive Testing to Identify Concrete Bridge Deck Deterioration (2012) / Chapter Skim
Currently Skimming:
Pages 68-77
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 68... ...
68 C h a p t e r 7 The performance of NDT technologies was generally evaluated from the perspective of five performance measures: accuracy, precision (repeatability) , ease of use, speed, and cost.
|
From page 69... ...
69 Table 7.1. Grading of NDT Technologies Based on Accuracy Defect Technology Participant Device Performance Parameters for Accuracy Grade Average Grade Maximum Grade Detectability Extent (WF = 0.3)
|
From page 70... ...
70 corroded rebar and the rest of the deck that was built with new rebar. The GPM, HCP, and ER technologies were marginally successful in reporting changes in parts of the deck that were constructed with the corroded rebar.
|
From page 71... ...
71 duct of the field validation testing. The data analysis and interpretation speed were graded on the basis of the information provided by the participants.
|
From page 72... ...
72 by a single parameter or a graphical output; and data interpretation. The grades are defined on the basis of the production rate.
|
From page 73... ...
73 Ease of Use The following parameters were considered in evaluating the ease of use of each technology: expertise in data collection, number of operators, ease of maneuvering, physical effort for the setup, expertise in data analysis, and potential for automation. The grades for some of the parameters are based on observations at sites where the tests were being performed, including expertise in data collection, number of operators, ease of maneuvering, and physical effort for setup and movement.
|
From page 74... ...
74 Cost The cost of an NDT method includes the following: • Cost of data collection. The cost of data collection is defined as the overall cost based on the workforce size, expertise level, and time needed to collect data.
|
From page 75... ...
75 traffic control is needed. On the basis of the speed calculated for each technique during the field validation testing in Haymarket, Virginia (Table 7.2)
|
From page 76... ...
76 speed changes with the level of deterioration because there is no postprocessing involved and testing and data analysis are performed simultaneously on the bridge. The deck of the Haymarket Bridge in Virginia, which was used in the field validation phase of the project, has significant signs of deterioration.
|
From page 77... ...
77 half-cell potential, galvanostatic pulse measurement, and ground-penetrating radar. However, ER and GPR will describe the corrosive environment of concrete to a greater extent, while GPM and HCP will describe corrosion rate and activity, respectively.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.