ASTM D4580-86(1997)
(Practice)Standard Practice for Measuring Delaminations in Concrete Bridge Decks by Sounding
Standard Practice for Measuring Delaminations in Concrete Bridge Decks by Sounding
SCOPE
1.1 This practice covers procedures for surveying concrete bridge decks by sounding to determine delaminations in the concrete. It is not intended that the procedures described herein are to be used on bridge decks that have been overlaid with bituminous mixtures. The procedures may be used on bridge decks that have been overlaid with portland cement concrete mixtures; however, areas indicated to be delaminated may have a lack of bond between the overlay and the underlying bridge deck (Note 1).
Note 1—The influence of variable field conditions such as traffic noise, vibration, moisture content of the concrete, and the like, are not completely known and additional investigation may be needed. It is generally agreed that the practice should not be used on frozen concrete.
1.2 The following three procedures are covered in this practice:
1.2.1 Procedure A, Electro-Mechanical Sounding Device—This procedure uses an electric powered tapping device, sonic receiver, and recorder mounted on a cart. The cart is pushed across the bridge deck and delaminations are recorded on the recorder.
1.2.2 Procedure B, Chain Drag—This procedure consists of dragging a chain over the bridge deck surface. The detection of delaminations is accomplished by the operator noting dull or hollow sounds. Tapping the bridge deck surface with a steel rod or hammer may be substituted for the chain drag.
1.2.3 Procedure C, Rotary Percussion—This procedure consists of rolling a dual-wheel, multi-toothed apparatus attached to an extension pole over the bridge deck surface. The percussive force caused by the tapping wheels will create either a dull or hollow sound indicating any delamination.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
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Designation: D 4580 – 86 (Reapproved 1997)
Standard Practice for
Measuring Delaminations in Concrete Bridge Decks by
Sounding
This standard is issued under the fixed designation D 4580; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope PROCEDURE A—ELECTRO-MECHANICAL
SOUNDING DEVICE
1.1 This practice covers procedures for surveying concrete
bridge decks by sounding to determine delaminations in the
3. Summary of Procedure
concrete. It is not intended that the procedures described herein
3.1 Longitudinal lines at a predetermined spacing are estab-
are to be used on bridge decks that have been overlaid with
lished on the bridge deck.
bituminous mixtures. The procedures may be used on bridge
3.2 After calibration, the sounding device is pushed along
decks that have been overlaid with portland cement concrete
the established lines. Electrically powered tapping wheels emit
mixtures; however, areas indicated to be delaminated may have
vibrations into the deck that are sensed by sonic receivers.
a lack of bond between the overlay and the underlying bridge
Areas of delamination are indicated by deflections on a strip
deck (Note 1).
chart recorder.
NOTE 1—The influence of variable field conditions such as traffic noise,
3.3 All portions on the strip chart indicating delaminations
vibration, moisture content of the concrete, and the like, are not com-
are plotted on a scaled map of the bridge deck. An outline is
pletely known and additional investigation may be needed. It is generally
made showing the areas of delamination.
agreed that the practice should not be used on frozen concrete.
1.2 The following two procedures are covered in this 4. Apparatus
practice:
NOTE 2—The apparatus described here has been found suitable and is
1.2.1 Procedure A, Electro-Mechanical Sounding Device—
the most common type commercially available. Other apparatuses that do
This procedure uses an electric powered tapping device, sonic
not exactly conform to these requirements such as sounding device,
receiver, and recorder mounted on a cart. The cart is pushed
tapping rate, or sonic receivers may also be accepted.
across the bridge deck and delaminations are recorded on the
4.1 Electro-Mechanical Sounding Device—A small, three-
recorder.
wheeled cart upon which is mounted a 12-V battery, two
1.2.2 Procedure B, Chain Drag—This procedure consists of
tapping wheels, two sonic receivers, a two-channel-strip re-
dragging a chain over the bridge deck surface. The detection of
corder, and associated connectors and cables.
delaminations is accomplished by the operator noting dull or
4.1.1 Tapping Wheels— Two rigid-steel-tapping wheels ca-
hollow sounds. Tapping the bridge deck surface with a steel rod
pable of tapping the bridge deck surface at the rate of 33
or hammer may be substituted for the chain drag.
times/s. The tapping wheels shall be located approximately 6
1.3 This standard does not purport to address all of the
in. (152 mm) apart.
safety concerns, if any, associated with its use. It is the
4.1.2 Sonic Receivers— Two sonic receivers consisting of
responsibility of whoever uses this standard to consult and
oil-filled soft tires, inside each of which a receiving transducer
establish appropriate safety and health practices and deter-
is mounted in nonrotating proximity to the concrete surface.
mine the applicability of regulatory limitations prior to use.
The transducers shall be piezo-electric hydrophones that are
coupled to the concrete surface through the soft tires and the oil
2. Significance and Use
within the wheels. Each receiving wheel shall be located
2.1 This practice may be used in conjunction with other
approximately 3 in. (76 mm) outside of and parallel to its
methods in determining the general condition of concrete
corresponding tapping wheel.
bridge decks.
4.1.3 Strip Chart Recorder—A two-channel-strip chart re-
2.2 This practice may be used in determining specific areas
corder shall be capable of receiving the signals from the sonic
of delamination requiring repair.
receivers. The electronics unit shall accept only those portions
of the signal that occur during the first 3 ms after the
occurrence of a tap and further limit the recorder to respond
This practice is under the jurisdiction of ASTM Committee D04 on Road and
only to those frequency components of the signal that lies in
Paving Materials and is the direct responsibility of Subcommittee D04.32 on
Bridges and Structures.
the range of 300 to 1200 Hz. The processed signals shall be
Current edition approved April 25, 1986. Published June 1986.
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D 4580
rectified and integrated to produce a visual record on the 8.3 Connect the limits of these plots and outline the indi-
respective channels of the record chart. The chart shall be vidual delaminated areas.
driven in proportion to the distance traveled so that the length 8.4 Determine the total area contained in the individual
of the record represents a predetermined length of travel. The delaminated areas.
recording pen on one channel shall be capable of acting as an 8.5 Divide the total delaminated area by the total bridge
event marker. deck area and multiply times 100 to yield the percent of deck
4.1.4 Cables and Connectors—There shall be sufficient area delaminated.
cables and connectors for connection of the left-tapping wheel
PROCEDURE B—CHAIN DRAG
sonic-receiver system to the left channel of the strip chart
recorder and the right-tapping wheel sonic-receiver system to
9. Summary of Procedure
the right channel of the strip chart recorder.
9.1 A grid system is laid out on the bridge deck.
4.2 Measuring Tape, Markers, Stringline—A measuring
9.2 Chains are dragged over the deck surface. Delaminated
tape, markers, and stringline shall be provided for establishing
areas are those where a dull or hollow sound from the chain
lines on the bridge deck that will serve to
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