Guide for Conducting Forensic Investigations of Highway Pavements (2013) / Chapter Skim
Currently Skimming:
Pages 17-28
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 17... ...
17 Forensic investigations are often undertaken because of the unclear reasons for specific pavement performance. Given this uncertainty, deciding on the most appropriate level of investigation is often difficult.
|
From page 18... ...
18 Complete non-destructive testing (NDT) Data analysis and NDT report Close out project Investigation issue(s)
|
From page 19... ...
19 • The district materials engineer (or similar position) : – Relates the issues being investigated to performance/ behavior of other roads in the area.
|
From page 20... ...
20 • Include an assessment of roadside conditions and activities that may contribute to the issues being investigated. Investigators are encouraged to observe, investigate, and document all possible contributing factors, recognizing that poor performance is often attributed to a number of reasons.
|
From page 21... ...
21 locations that should be avoided if possible, such as ramps, curves, intersections, and rises. – Work on underground services and utilities (i.e., distress may be associated with utility failure/work)
|
From page 22... ...
22 thickness variation, stripping, and possibly debonding. They can be operated at highway speeds; however, data quality decreases with increasing speed and a closure may be required to obtain more accurate results.
|
From page 23... ...
23 Key issues to consider include: • Ensure that the equipment has a valid calibration certificate. • On rutted asphalt pavements, test in between the wheelpaths to ensure that the plate seats firmly on the surface.
|
From page 24... ...
24 • ASTM D4694, Standard Test Method for Deflections with a Falling-Weight-Type Impulse Load Device. • ASTM D4695, Guide for General Pavement Deflection Measurements.
|
From page 25... ...
25 4.2.4.2. Examples of the Use of NDT in Forensic Investigations Examples of how NDT is used in forensic investigations are provided in Table 4.1 for asphalt surfaced pavements and in Table 4.2 for concrete surfaced pavements.
|
From page 26... ...
26 Issue Possible Contributing Factors Type of Non-Destructive Testing Typical Testing Frequency Exceptional performance Design Construction Materials GPR, FWD GPR, FWD, nuclear gauge GPR, FWD - GPR: continuous (2 scans/yd [m]
|
From page 27... ...
27 Issue Possible Contributing Factors Type of Non-Destructive Testing Typical Testing Frequency Exceptional performance Design Construction Materials GPR1, FWD1 Profilometer, OBSI GPR, FWD - GPR: continuous (2 scans/yd [m]
|
From page 28... ...
28 pre-investigation site visit, and to provide details of the NDT, the results of which will be used to finalize the investigation plan. The initial plan should include the following (example Form #11 in Appendix C)
|
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.