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Concrete Deck—Spalls and Delamination - Ltbp Protocol - Fld-Dc-Vic-003

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

	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.

Page Owner: Office of Research, Development, and Technology, Office of Corporate Research, Technology, and Innovation Management

Topics: research, infrastructure, structures
Keywords: research, structures, LTBP Program, bridge performance, bridge testing, bridge inspection, Bridge, bridge inspection, Long-Term Bridge Performance Program, LTBP, testing protocols, data collection
TRT Terms: research, infrastructure, Facilities, Structures
Scheduled Update: Archive - No Update needed

This page last modified on 03/24/2017

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

Concrete Deck—Spalls and DelaminationLTBP Protocol #: FLD-DC-VIC-003

1.

Data Collected

2.

Onsite Equipment and Personnel Requirements

3.

Methodology

4.

Data Collection Table

5.

Criteria for Data Validation

6.

Commentary/Background

7.

References

Concrete Deck—Spalls and Delamination
LTBP Protocol #: FLD-DC-VIC-003