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REPORT
This report is an archived publication and may contain dated technical, contact, and link information
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Publication Number:  FHWA-HRT-16-007    Date:  January 2016
Publication Number: FHWA-HRT-16-007
Date: January 2016

 

Long-Term Bridge Performance (LTBP) Program Protocols, Version 1

Long-Term Bridge Performance Program Logo

Concrete Superstructure and Substructure—Spalls and Delaminations
LTBP Protocol #: FLD-DC-VIC-004


1.

Data Collected

 
1.1 Description and location of spalls and delaminations on concrete superstructures and substructures.  

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 Sounding hammer.  
2.1.4 Wire brush or hand broom.  
2.1.5 Tape measure.  
2.1.6 6-ft folding rule.  
2.1.7 Caliper.  
2.1.8 Waders or a boat (if necessary).  
2.1.9 Laser measuring device (optional).  
2.1.10 Temporary marker.  
2.1.11 Digital camera.  
2.1.12 Pencil, sketch pad, clipboard.  
2.2 Personnel: PRE-PL-LO-005, Personnel Qualifications.  

3.

Methodology

 
3.1 Use the segmentation and numbering system (FLD-OP-SC-002, Structure Segmentation and Element Identification System) to locate and document defects 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 of the superstructure and substructure. Establish the two relevant coordinate axes for each face of each element being evaluated.  
3.3 Cleaning: Use the wire brush or hand broom to clean the concrete element by brushing away any debris so any defects are visible.  
3.4 Measuring, recording, and evaluating characteristics of spalls and delaminations:  
3.4.1 For any suspected defect area, strike the concrete surface with a sounding hammer, and listen for any hollow sounding areas in concrete; remove any loose concrete.  
3.4.2 Mark the limits of each area of delamination or spalling on the element with a temporary marker, and mark the corners of a rectangle that encompasses the maximum length and maximum width of the area of delamination or spalling.  
3.4.3 Measure and record the dimensions of each area of delamination or spalling at its maximum length and width.  
3.4.4 For each area of delamination or spalling on the element, document on which superstructure or substructure element (FLD-OP-SC-002, Structure Segmentation and Element Identification System) and on what area of the element the delamination or spalling is located. Using the element local origin as point (0,0,0), determine and record the coordinates of the four corners of the rectangle.  
3.5 For each instance of exposed steel reinforcement and tendons or strands:  
3.5.1 Record the type and unique element identifier of the element where the steel reinforcement and/or tendons or strands are exposed.  
3.5.2 Mark the length of the exposed steel reinforcement and/or tendons or strands with a temporary marker, and photograph the damage.  
3.5.3 Measure the length of the exposed steel reinforcement and/or tendons or strands.  
3.5.4 Document the location of exposed steel reinforcement and/or tendons or strands by determining and recording the coordinates of the beginning and the end of the affected portion of the element.  
3.5.5 Clean with a wire brush, and measure and record the amount of section loss in the exposed steel reinforcement and/or tendons or strands (if applicable). If necessary, obtain the original cross‑section from the existing documentation for the bridge (PRE-ED-BD-001, Plans and Specifications for Bridge Design and Construction).  
3.6 Documenting defects:  
3.6.1 Take photographs of defects using FLD-DC-PH-002, Photographing for Documentation Purposes, and create a photo log.  
3.6.2 Use sketches to document spalls and delaminations and supplement the photographs.  
3.7 Storing data, documents, and images:  
3.7.1 FLD-DS-LS-001, Data, Document, and Image Storage—Local, for local storage.  
3.7.2 FLD-DS-RS-001, Data, Document, and Image Storage—Remote, for remote storage.  
3.8 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 Spalls and Delaminations
Pink
8 Location of the defect: element type and identifier
Text
 
 
Example: Pier P1; evaluate each element individually and record data on each individual defect
Blue
9 Location of the defect on the element
Text
 
 
Example: top of pier cap
Yellow
10 Type of defect
Text
 
 
Delamination
Spall
Yellow
11 Pair of coordinates used to locate the defect on element
Text
 
 
(x,y), (x,z), or (y,z)
Yellow
12 Location of corner 1
Number
1
in.

(x,y) coordinates of the four corners of a rectangle encompassing the deteriorated area

Yellow
13 Location of corner 2
Number
1
in.
Yellow
14 Location of corner 3
Number
1
in.
Yellow
15 Location of corner 4
Number
1
in.
Yellow
16 Maximum length of the defect
Number
1
in.
 
Yellow
17 Maximum width of the defect
Number
1
in.
 
Yellow
18 Maximum depth of the defect
Number
0.125
in.
 
Yellow
19 Defect photos and/or sketches
BLOB
 
 
Document typical defects with photos and/or sketches
Yellow
20 Comments
Text
 
 
 
Orange
For Exposed Steel Reinforcement and/or Tendons/Strands
Pink
21 Location of the defect: element type and identifier
Text
 
 
Example: Girder 1A; evaluate each element individually and record data on each individual defect
Blue
22 Location of the defect on the element
Text
 
 
Example: bottom flange of girder
Yellow
23 Condition of reinforcement and/or prestressing strands or tendons
Text
 
 
Visible corroded section,
Loss of section, and/or
Other (specify under comments)
Yellow
24 Location of the beginning of the defect: x-coordinate
Number
1
in.
Measured from the element local origin to the beginning of the defect

Yellow
25 Location of the end of the defect: x‑coordinate
Number
1
in.
Measured from the element local origin to the end of the defect
Yellow
26 Length of defect
Number
1
in.
 
Yellow
27 Defect photos
BLOB
 
 
Document typical defects with photos and/or sketches
Yellow
28 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 that 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 appropriate protocols.  

6.

Commentary/Background

 
6.1 This protocol provides guidance on locating and measuring the extent of spalls and delaminations on concrete superstructure and substructure elements.  
6.2 A spall is a depression in concrete caused by a separation of a portion of the surface concrete, revealing a fracture parallel with or slightly inclined to the surface. A delamination is a surface separation of concrete into layers. Spalls and delaminations may have numerous and distinct causes, including the following:  
6.2.1 Collisions.  
6.2.2 Earthquakes.  
6.2.3 Overstresses.  
6.2.4 Alkali-silica reaction (ASR).  
6.2.5 Reinforcement/prestressing corrosion.  
6.2.6 Formation of ettringite.  
6.2.7 Freeze-thaw cycling.  
6.3 Spalls are identified by a loss of concrete material from the surface and may be several inches deep. A delamination might eventually result in a loss of material (i.e., become a spall). Both defects may change the structural performance of the component or expose reinforcement or prestressing tendons/strands to corrosive agents.  

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 PRE-ED-BD-001, Plans and Specifications for Bridge Design and Construction.  
7.1.4 FLD-OP-SC-002, Structure Segmentation and Element Identification System.  
7.1.5 FLD-OP-SC-003, Determination of Local Origins for Elements.  
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.  

 

 

 

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