1. |
Data Collected |
|
| 1.1 |
Description and location of corrosion on a steel superstructure. |
|
|
2. |
Onsite Equipment and Personnel Requirements |
|
| 2.1 |
Equipment: |
|
| 2.1.1 |
PRE-PL-LO-004, Personal Health and Safety Plan. |
|
| 2.1.2 |
Ladder, access platform, snooper, bucket truck, man lift, and/or high-reach equipment (if necessary). |
|
| 2.1.3 |
Tape measure. |
|
| 2.1.4 |
6-ft folding rule. |
|
| 2.1.5 |
Scraper. |
|
| 2.1.6 |
Wire brush or hand broom. |
|
| 2.1.7 |
Sounding hammer. |
|
| 2.1.8 |
Lever pit gage. |
|
| 2.1.9 |
Slide caliper. |
|
| 2.1.10 |
Laser measuring device (optional). |
|
| 2.1.11 |
Temporary marker. |
|
| 2.1.12 |
Digital camera. |
|
| 2.1.13 |
Pencil, sketch pad, and clipboard. |
|
| 2.2 |
Personnel: PRE-PL-LO-005, Personnel Qualifications. |
|
|
3. |
Methodology |
|
| 3.1 |
Use the segmentation and numbering system for the superstructure (FLD-OP-SC-002, Structure Segmentation and Element Identification System) so defects can be located and noted by the unique element identifier. |
|
| 3.2 |
Use FLD-OP-SC-003, Determination of Local Origins for Elements, to establish a local origin on each element to be used to locate defects. |
|
| 3.3 |
Cleaning: |
|
| 3.3.1 |
Use the scraper and wire brush to clean loose, deteriorated protective coating and surface corrosion, if any are present. |
|
| 3.3.2 |
If after cleaning, section loss to the steel is evident, follow FLD-DC-VIS-003, Steel Superstructure—Section Loss, to record measurements and characteristics of the section loss. |
|
| 3.4 |
Measuring, recording, and evaluating characteristics of corrosive activity: |
|
| 3.4.1 |
Mark the limits of each area with deteriorated coatings on the element with a temporary marker, and mark the corners of a rectangle that encompasses the maximum length and maximum width of the corroded area. |
|
| 3.4.1.1 |
Using the element local origin as point (0,0,0), determine and record the coordinates of the four corners of the rectangle. |
|
| 3.4.1.2 |
Measure the maximum length and width of the area with deteriorated coatings. |
|
| 3.4.2 |
Mark the limits of each corroded area on the element with a temporary marker, and mark the corners of a rectangle that encompasses the maximum length and maximum width of the corroded area. |
|
| 3.4.2.1 |
Using the element local origin as point (0,0,0), determine and record the coordinates of the four corners of the rectangle. |
|
| 3.4.2.2 |
Measure the maximum length and width of the corrosion. |
|
| 3.4.3 |
Determine the extent (depth) and severity of any pitting using a lever pit gage. |
|
| 3.5 |
Documenting defects: |
|
| 3.5.1 |
Take photographs of defects using FLD-DC-PH-002, Photographing for Documentation Purposes, and create a photo log. |
|
| 3.5.2 |
Use sketches as needed to document section loss and cracking and supplement the photographs. |
|
| 3.6 |
Storing data, documents, and images: |
|
| 3.6.1 |
FLD-DS-LS-001, Data, Document, and Image Storage—Local, for local storage. |
|
| 3.6.2 |
FLD-DS-RS-001, Data, Document, and Image Storage—Remote, for remote storage. |
|
| 3.7 |
Reporting: Transfer all metadata, data, documents, and images to Federal Highway Administration (FHWA), and/or upload all metadata, data, documents, and images into the Long-Term Bridge Performance (LTBP) Bridge Portal. |
|
|
4. |
Data Collection Table |
|
| 4.1 |
Table: |
|
| # |
Field Name |
Data Type |
Accuracy |
Unit |
Field Description |
Row Color |
| 1 |
State |
Text |
|
|
State Code; e.g., Virginia = VA |
Green |
| 2 |
NBI structure number |
Text |
|
|
Item 8, structure number; from NBI Coding Guide |
Green |
| 3 |
Structure name |
Text |
|
|
Descriptive name for the bridge; e.g., Route 15 SB over
I–66 |
Green |
| 4 |
Protocol name |
Text |
|
|
Title of the protocol |
Green |
| 5 |
Protocol version |
Text |
Month and year |
|
Month and year the protocol version was published; e.g., May 2015 |
Green |
| 6 |
Personnel performing data collection activities |
Text |
|
|
First name(s) Last name(s) |
Green |
| 7 |
Date data were collected |
Text |
Exact date |
|
mm/dd/yyyy |
Green |
| For Coating Deterioration |
Pink |
| 8 |
Location of deteriorated coating: element type and unique identifier |
Text |
|
|
Example: Girder, 1A; evaluate and record data for areas of deteriorated coating on each individual element |
Blue |
| 9 |
Location of defect on the element |
Text |
|
|
Example: bottom flange of girder 1A |
Blue |
| 10 |
Type of defect |
Text |
|
|
Chalking
Cracking
Loss of adhesion
Peeling
Other (specify) |
Yellow |
| 11 |
Location of corner 1 |
Number |
1 |
in. |
(x,y,z) coordinates of the four corners of a rectangle encompassing the deteriorated area |
Yellow |
| 12 |
Location of corner 2 |
Number |
1 |
in. |
Yellow |
| 13 |
Location of corner 3 |
Number |
1 |
in. |
Yellow |
| 14 |
Location of corner 4 |
Number |
1 |
in. |
Yellow |
| 15 |
Maximum length of deteriorated coating area |
Number |
1 |
in. |
Measured parallel to the x-axis |
Yellow |
| 16 |
Maximum width of deteriorated coating area |
Number |
1 |
in. |
Measured parallel to the z-axis |
Yellow |
| 17 |
Defect photos and sketches |
BLOB |
BLOB |
|
Document typical areas of deteriorated coating with photos and/or sketches |
Yellow |
| 18 |
Comments |
Text |
|
|
|
Orange |
| For Corrosion |
Pink |
| 19 |
Location of corroded area: element type and unique identifier |
Text |
|
|
Example: Girder, 1A; evaluate and record data for corroded areas on each individual element |
Blue |
| 20 |
Location of defect on the element |
Text |
|
|
Example: web of girder 1A |
Blue |
| 21 |
Location of corroded area on member – corner 1 |
Number |
1 |
in. |
(x,y) coordinates of the four corners of a rectangle encompassing the deteriorated area |
Yellow |
| 22 |
Location of corner 2 |
Number |
1 |
in. |
Yellow |
| 23 |
Location of corner 3 |
Number |
1 |
in. |
Yellow |
| 24 |
Location of corner 4 |
Number |
1 |
in. |
Yellow |
| 25 |
Maximum length of corroded area |
Number |
1 |
in. |
Measured parallel to the x-axis |
Yellow |
| 26 |
Maximum width of corroded area |
Number |
1 |
in. |
Measured parallel to the z-axis |
Yellow |
| 27 |
Depth of pitting |
Number |
0.01 |
in. |
|
Yellow |
| 28 |
Defect photos and sketches |
BLOB |
|
|
Document typical corroded areas with photos and/or sketches |
Yellow |
| 29 |
Comments |
Text |
|
|
|
Orange |
|
| 4.2 |
Table Key: |
|
| Column Descriptions |
# |
Sequential number of data item |
Field Name |
Data field name |
Data Type |
Type of data, such as text, number, predefined list, binary large object (BLOB), or PDF file |
Accuracy |
Accuracy to which the data are recorded |
Unit |
Unit in which a measurement is taken and recorded |
Field Description |
Commentary on the data or list of items in a predefined list |
| Row Color Key |
Green |
Data items only entered once for each protocol for each day the protocol is applied |
Pink |
Logical breakdown of data by elements or defect types (not always used) |
Blue |
Data identifying the element being evaluated or the type of defect being identified |
Yellow |
LTBP data reported individually for each element or defect identified |
Orange |
Comments on the data collection or data entered |
|
|
5. |
Criteria for Data Validation |
|
| 5.1 |
Compare measurements with measurements from previous inspections of the same structure to make sure values make sense. |
|
| 5.2 |
Compare measurements with photo documentation to make sure results shown in photos are consistent with items measured. |
|
| 5.3 |
If an element’s condition is improved when compared to the condition documented in a previous inspection, check with the State department of transportation to determine if any maintenance, repair, and/or bridge preservation actions have occurred. If so, document these maintenance, repair, and/or bridge preservation actions using the appropriate protocols. |
|
|
6. |
Commentary/Background |
|
| 6.1 |
This protocol provides guidance on identifying corroded areas on steel superstructure elements and documenting their extent and location on the element. Guidance is also provided for measuring the extent and depth of any pitting of the steel is present. |
|
| 6.2 |
Steel superstructures, such as trusses (deck, through, and pony), multigirder beams, girder/floor beam/stringer systems, box girders, etc., that are not built of weathering steel and are not protected by galvanizing or metallizing are usually protected by one or more coats of paint to guard against oxidation (rusting) of the steel. |
|
| 6.3 |
The most common types of defects in bridge coatings include chalking, cracking, loss of adhesion, and peeling. Data collection involves identifying areas where coating defects are evident and documenting the location and size of the affected areas. |
|
| 6.4 |
The main cause of steel corrosion in coated bridges is the lack and/or breakdown of the protective coating. Once this occurs, the exposure to corrosive agents (water, salts, and chemicals) begins a disintegration process on the surface metal. Corrosion grows from a few, small starting points, and then expands as steel molecules that are directly in contact with the corroded area also corrode; eventually, small, medium, and large contiguous areas of corrosion are evident. Data collection involves identifying areas where corrosion is evident and documenting the location and size of the affected areas. |
|
|
7. |
References |
|
| 7.1 |
LTBP Protocols: |
|
| 7.1.1 |
PRE-PL-LO-004, Personal Health and Safety Plan. |
|
| 7.1.2 |
PRE-PL-LO-005, Personnel Qualifications. |
|
| 7.1.3 |
FLD-OP-SC-002, Structure Segmentation and Element Identification System. |
|
| 7.1.4 |
FLD-OP-SC-003, Determination of Local Origins for Elements. |
|
| 7.1.5 |
FLD-DC-VIS-003, Steel Superstructure—Section Loss. |
|
| 7.1.6 |
FLD-DC-PH-002, Photographing for Documentation Purposes. |
|
| 7.1.7 |
FLD-DS-LS-001, Data, Document, and Image Storage—Local. |
|
| 7.1.8 |
FLD-DS-RS-001, Data, Document, and Image Storage—Remote. |
|
| 7.2 |
External: |
|
| 7.2.1 |
FHWA-NHI-12-053, Bridge Inspector’s Reference Manual, Federal Highway Administration, Washington, DC, 2012. |
|
