U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000


Skip to content
FacebookYouTubeTwitterFlickrLinkedIn

Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

 
REPORT
This report is an archived publication and may contain dated technical, contact, and link information
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 Deck—Spalls and Delamination
LTBP Protocol #: FLD-DC-VIC-003


1.

Data Collected

 
1.1 Description and location of spalls and delaminations on concrete deck.  

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 Chain or a series of medium weight chains attached to a T-shaped handle.  
2.1.4 Sounding hammer.  
2.1.5 Wire brush or hand broom.  
2.1.6 Tape measure.  
2.1.7 6-ft folding rule.  
2.1.8 Measuring wheel.  
2.1.9 Laser measuring device (optional).  
2.1.10 Temporary marker.  
2.1.11 Digital camera.  
2.1.12 Pencil, sketch pad, and clipboard.  
2.2 Personnel: PRE-PL-LO-005, Personnel Qualifications.  

3.

Methodology

 
3.1 Use the data collection grid (FLD-OP-SC-001, Data Collection Grid and Coordinate System for Bridge Decks) to locate defects on the deck.  
3.2 Cleaning:  
3.2.1 Use the wire brush or hand broom to clean the concrete element by brushing away any debris so any defects are visible.  
3.2.2 Remove, collect, and discard all concrete that is loose enough to move without fracturing additional surfaces.  
3.3 Deck delamination survey:  
3.3.1 Using a sweeping motion, pull the chain drag over approximately 3 ft of the concrete deck surface at a time, with only the chains dragging on the deck surface. Listen for the sound of ringing chains to change to a hollow, dull, popping sound as the chains go over the surface of a delamination.  
3.3.2 Once the chain drag has detected a debonded area, determine the size and edges of the delamination by using a hand-held sounding hammer. Lightly tap the area where the hollow sound is heard, and work in a line.  
3.3.3 Using a temporary marker, outline the boundary of each individual area of the deck surface where the hollow sound is heard. Add a hatch pattern to the area to clearly show the area on the deck in pictures. Mark the corners of a rectangle that encompasses the maximum length and maximum width of the area of spalling or delamination.  
3.3.4 Measure and record the dimensions of each area of delamination or spalling at its maximum length and width.  
3.3.5 For each area of delamination or spalling on the deck, determine and record the coordinates of the four corners of the rectangle using x and y coordinates from the rectangular grid system (FLD‑OP‑SC‑001, Data Collection Grid and Coordinate System for Bridge Decks).  
3.4 For each instance of exposed steel reinforcement and/or tendons or strands:  
3.4.1 Using a temporary marker, outline the boundary of each individual area of the deck surface where the steel reinforcement and/or tendons or strands are exposed. Also, mark the corners of a rectangle that encompasses the maximum length and maximum width of the area of spalling or delamination.  
3.4.2 Measure and record the dimensions of each area of exposed steel reinforcement and/or tendons or strands at its maximum length and width.  
3.4.3 For each area of exposed steel reinforcement and/or tendons or strands on the deck, determine and record the coordinates of the four corners of the rectangle using x and y coordinates from the rectangular grid system (FLD-OP-SC-001, Data Collection Grid and Coordinate System for Bridge Decks).  
3.4.4 Clean with a wire brush, and measure and record the amount of section loss in the exposed steel reinforcement and 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).  
3.5 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 spall and/or delamination 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 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 Delaminations and Spalls on the Deck
Pink
8 Location of defect: span number
Text
 
 
Example: Span 1; evaluate each span individually, and record data on each individual defect
Blue
9 Location of defect on the deck
Text
 
 
Describe the location of defect on the deck e.g., lane number, right or left shoulder
Yellow
10 Type of defect
Text
 
 
Delamination or
Spall
Yellow
11 Location of corner 1
Number
1
in.
(x,y) 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 defect
Number
1
in.
Measured parallel to the x-axis
Yellow
16 Maximum width of defect
Number
1
in.
Measured parallel to the y-axis
Yellow
17 Maximum depth of defect
Number
0.125
in.
 
Yellow
18 Defect photos and sketches
Number
0.125
in.
Document typical abraded areas with photos and/or sketches
Yellow
19 Comments
Text
 
 
 
Orange
For Exposed Steel Reinforcement and/or Tendons/Strands
Pink
20 Location of defect: span number
Text
 
 
Example: Span 1; evaluate each span individually, and record data on each individual defect
Blue
21 Location of defect on the deck
Text
 
 
Describe the location of defect on the deck e.g., lane number, right or left shoulder
Yellow
22 Condition of reinforcement and/or prestressing strands or tendons
Text
 
 
Steel reinforcement and/or prestressing strands or tendons not exposed,
Visible corroded section,
Loss of section, and/or
Other (specify under comments)
Yellow
23 Location of corner 1
Number
1
in.
(x,y) coordinates of the four corners of a rectangle encompassing the deteriorated area
Yellow
24 Location of corner 2
Number
1
in.
Yellow
25 Location of corner 3
Number
1
in.
Yellow
26 Location of corner 4
Number
1
in.
Yellow
27 Maximum length defect
Number
1
in.
Measured parallel to the x-axis
Yellow
28 Maximum width of defect
Number
1
in.
Measured parallel to the y-axis
Yellow
29 Maximum depth of defect
Number
0.125
in.
 
Yellow
30 Defect photos and sketches
Number
0.125
in.
Document typical abraded areas with photos and/or sketches
Yellow
31 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 decks and for conducting a chain drag survey in which the sounds from chains dragged over a concrete surface are used to detect delaminations. A dull or hollow sound of the chain links indicates delaminated areas, and a clear ringing sound indicates nondelaminated concrete.

NOTE— Sounding may be more difficult in areas of significant traffic or other noises.
 
6.2 The chain drag is an easy and inexpensive method of locating delaminations on bridge decks. This procedure can require multiple technicians if the structure is long and/or has multiple lanes. Refer to ASTM D4580/D4580M-12, Standard Practice for Measuring Delaminations in Concrete Bridge Decks by Sounding, for further guidance on proper chain types and configurations.  
6.3 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 on a structure, including the following:  
6.3.1 Collisions.  
6.3.2 Earthquakes.  
6.3.3 Overstresses.  
6.3.4 Alkali-silica reaction (ASR).  
6.3.5 Reinforcement/prestressing corrosion.  
6.3.6 Formation of ettringite.  
6.3.7 Freeze-thaw cycling.  
6.4 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 or 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-001, Data Collection Grid and Coordinate System for Bridge Decks.  
7.1.5 FLD-DC-PH-002, Photographing for Documentation Purposes.  
7.1.6 FLD-DS-LS-001, Data, Document, and Image Storage—Local.  
7.1.7 FLD-DS-RS-001, Data, Document, and Image Storage—Remote.  
7.2 External:  
7.2.1 Federal Highway Administration (FHWA)-NHI-12-053, Bridge Inspector’s Reference Manual, Federal Highway Administration, Washington, DC, 2012.  
7.2.2 ASTM D4580/D4580M-12, Standard Practice for Measuring Delaminations in Concrete Bridge Decks by Sounding, ASTM International, West Conshohocken, PA, 2012.  

 

 

 

Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000
Turner-Fairbank Highway Research Center | 6300 Georgetown Pike | McLean, VA | 22101