ASTM D6087-97e1

Standard Test Method for Evaluating Asphalt-Covered Concrete Bridge Decks Using Ground Penetrating Radar

SCOPE
1.1 This test method covers several radar evaluation procedures that can be used to evaluate the condition of concrete bridge decks overlaid with asphaltic concrete wearing surfaces. Specifically, this test method predicts the presence or absence of delamination.
1.2 The most serious form of deterioration is that which is caused by corrosion of embedded reinforcement. Corrosion is initiated by deicing salts, used for snow and ice control in the winter months, penetrating the concrete. In arid climates, the corrosion can be initiated by chloride ions contained in the mix ingredients.
1.2.1 As the reinforcing steel corrodes, it expands and creates a crack or subsurface fracture plane in the concrete at or just above the level of the reinforcement. The fracture plane, or delamination, may be localized or may extend over a substantial area, especially if the concrete cover to the reinforcement is small. It is not uncommon for more than one delamination to occur on different planes between the concrete surface and the reinforcing steel. Delaminations are not visible on the concrete surface. However, if repairs are not made, the delaminations progress to open spalls and, with continued corrosion, eventually affect the structural integrity of the deck.
1.3 This test method may not be suitable for evaluating bridges with delamination which are localized over the diameter of the reinforcement, or for those bridges which have cathodic protection (coke breeze as cathode) installed on the bridge or for which a conductive aggregate has been used in the asphalt (that is, blast furnace slag). This is because metals are perfect reflectors of EM waves, since the wave impedances for metals are zero.
1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only. Specific precautionary statements are given in Section 5.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Mar-1997
• Technical Committee: D04 - Road and Paving Materials
• Drafting Committee: D04.32 - Bridges and Structures

Relations

• Replaced By: ASTM D6087-97(2001) - Standard Test Method for Evaluating Asphalt-Covered Concrete Bridge Decks Using Ground Penetrating Radar
• Effective Date: 10-Mar-1997

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
e1
Designation: D 6087 – 97
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Evaluating Asphalt-Covered Concrete Bridge Decks Using
1
Ground Penetrating Radar
This standard is issued under the fixed designation D 6087; 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
e NOTE—Equations 6, 7, and 8 were corrected editorially in October 1998.
1. Scope responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 This test method covers several radar evaluation proce-
bility of regulatory limitations prior to use.
dures that can be used to evaluate the condition of concrete
bridge decks overlaid with asphaltic concrete wearing surfaces.
2. Summary of Test Method
Specifically, this test method predicts the presence or absence
2.1 A vehicle equipped with a short-pulse ground penetrat-
of delamination.
ing radar, data acquisition device, recording device, and data
1.2 The most serious form of deterioration is that which is
processing and interpretation equipment makes repeated
caused by corrosion of embedded reinforcement. Corrosion is
passes, parallel to centerline across an asphalt covered bridge
initiated by deicing salts, used for snow and ice control in the
deck at specified locations. Bridge deck condition is quantified
winter months, penetrating the concrete. In arid climates, the
based on the data obtained.
corrosion can be initiated by chloride ions contained in the mix
ingredients.
3. Significance and Use
1.2.1 As the reinforcing steel corrodes, it expands and
3.1 This test method provides information on the condition
creates a crack or subsurface fracture plane in the concrete at
of concrete bridge decks overlaid with asphaltic concrete
or just above the level of the reinforcement. The fracture plane,
without necessitating removal of the overlay, or other destruc-
or delamination, may be localized or may extend over a
tive procedures.
substantial area, especially if the concrete cover to the rein-
3.2 A systematic approach to bridge deck rehabilitation
forcement is small. It is not uncommon for more than one
requires considerable data on the condition of the decks. In the
delamination to occur on different planes between the concrete
past, data has been collected using the traditional methods of
surface and the reinforcing steel. Delaminations are not visible
visual inspection supplemented by physical testing and coring.
on the concrete surface. However, if repairs are not made, the
Such methods have proven to be tedious, expensive and of
delaminations progress to open spalls and, with continued
limited accuracy. Consequently, radar provides a mechanism to
corrosion, eventually affect the structural integrity of the deck.
rapidly survey bridges in a non-contact, non-destructive man-
1.3 This test method may not be suitable for evaluating
ner.
bridges with delaminations which are localized over the
3.3 Information on the condition of asphalt-covered, con-
diameter of the reinforcement, or for those bridges which have
crete bridge decks is needed to estimate bridge deck condition
cathodic protection (coke breeze as cathode) installed on the
for maintenance and rehabilitation, to provide cost-effective
bridge or for which a conductive aggregate has been used in the
information necessary for rehabilitation contracts.
asphalt (that is, blast furnace slag). This is because metals are
perfect reflectors of EM waves, since the wave impedances for
4. Apparatus
metals are zero.
4.1 Radar System—Air-coupled, short-pulse monostatic ra-
1.4 The values stated in SI units are to be regarded as the
dar(s) with a monocycle pulse, 150 mm (6 in.) free space
standard. The inch-pound units given in parentheses are for
resolution and a 50 scan/s data rate, minimum.
information only. Specific precautionary statements are given
4.2 Data Acquisition System—A data acquisition system,
in Section 5.
consisting of equipment for gathering radar data at the maxi-
1.5 This standard does not purport to address all of the
mum data rate of the radar system(s), 50 kHz for one radar, 100
safety concerns, if any, associated with its use. It is the
kHz for two radars, and 150 kHz for three radars. The system
shall be capable of accurately acquiring radar data with a 60 dB
1
This test method is under the jurisdiction of ASTM Committee D-4 on Road
dynamic range.
and Paving Materials and is the direct responsibility of Subcommittee D04.32 on
...