ASTM D6948/D6948M-03(2023)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D6948/D6948M −03 (Reapproved 2023)
Standard Practice for
Application of Refined Coal Tar (Ready to Use, Commercial
Grade)
This standard is issued under the fixed designation D6948/D6948M; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope Tar (Ready to Use, Commercial Grade)
1.1 This practice covers the application of emulsified re-
3. Terminology
fined coal tar slurry meeting the requirements of Specification
D6945/D6945M Types I and II, by mechanized equipment as a
3.1 Two types of mixtures are defined in Specification
weather protection and petroleum (aliphatic) solvent resistant
D6945/D6945M. The ingredients for both types of mixtures
sealer for use on bituminous concrete pavements. In order to
are normally combined at the contractor’s yard or at the job
clarify the differences between Types I and II, see 3.3 for
site. Refined coal tar emulsion meeting Specification D5727/
standard definition of terms.
D5727M is concentrated when shipped from the manufacturer
to the applicator.
1.2 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in 3.1.1 Specification D6945/D6945M Type I material—is
Specification D5727/D5727M material diluted with water
each system may not be exact equivalents; therefore, each
system shall be used independently of the other. Combining typically by the applicator after which aggregate is added.
values from the two systems may result in nonconformance
3.1.2 Specification D6945/D6945M Type II material—is
with the standard.
Specification D5727/D5727M material diluted with water
typically by the applicator after which additive and aggregate
1.3 This standard does not purport to address all of the
is added.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
3.2 The mixtures described in 3.1.1 and 3.1.2 can be
priate safety, health, and environmental practices and deter-
submitted to a laboratory approved by the owner for testing of
mine the applicability of regulatory limitations prior to use.
their conformance to Specification D6945/D6945MTypeIor
1.4 This international standard was developed in accor-
Type II prior to their actual use on the job.
dance with internationally recognized principles on standard-
3.3 Definitions:
ization established in the Decision on Principles for the
3.3.1 additive—one or more ingredients that can be added to
Development of International Standards, Guides and Recom-
a specific refined coal tar emulsion, water, or sand (or combi-
mendations issued by the World Trade Organization Technical
nationthereof)mixturetoimprovethecoatings’durability,fuel
Barriers to Trade (TBT) Committee.
resistance, drying time, color uniformity, or length of time
2. Referenced Documents required before opening the surface to traffic, or combination
thereof. This material can also be used to modify the wet
2.1 ASTM Standards:
mixture’s viscosity to improve aggregate suspension. Because
D490 Specification for Road Tar
there is such a wide variance of additives on the market, the
D5727/D5727M Specification for Emulsified Refined Coal
aforementioned results may not take place. If an additive is
Tar (Mineral Colloid Type)
used, it is recommended that it be supplied by the same
D6945/D6945M Specification for Emulsified Refined Coal-
manufacturer as the refined coal tar emulsion.
3.3.2 application rate—the volume of mixed materials ap-
ThispracticeisunderthejurisdictionofASTMCommitteeD08onRoofingand
plied per area of pavement surface, usually expressed in liters
Waterproofing and is the direct responsibility of Subcommittee D08.09 on Liquid
2 2
per square meter (L/m ) [gallons per square yard (gal/yd )].
Applied Coatings for Roofing and Asphaltic Concrete Pavement.
Current edition approved Jan. 1, 2023. Published January 2023. Originally
3.3.3 applied mixture—the combination of all ingredients
approved in 2003. Last previous edition approved in 2017 as D6948/D6948M – 03
mixed together and ready for application to the pavement.Also
(2017). DOI: 10.1520/D6948_D6948M-03R23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or referred to as seal coat or sealer.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
3.3.4 bituminous concrete pavements, new—pavements that
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. have been placed less than 90 days.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6948/D6948M−03 (2023)
3.3.5 bituminous concrete pavements, aged—pavements 3.3.21 uniform coated surface—a surface that has an even
that weathered over at least one summer season and have distribution of seal coating material free of pinholes, streaks, or
shown signs of one or more of the following: cracking, other uneven characteristics, or combination thereof.
raveling, aggregate polishing or graying due to oxidation, or
4. Significance and Use
combination thereof.
4.1 This practice is designed as a guide for architects,
3.3.6 brush applicator—a hand-type or mechanized brush
engineers, property owners or their representatives, or combi-
used to apply pavement sealer.
nation thereof. Its use helps ensure the satisfactory perfor-
3.3.7 crack filler—a material that is placed in a pavement
mance of the protective coating system when applied over
crack or joint to fill but not necessarily seal the void created by
bituminous concrete pavements.
the crack or joint.
5. Materials
3.3.8 crack sealant—a material that has adhesive and cohe-
5.1 Refined Coal Tar Emulsion (Seal Coating) Mixture—A
sive properties to seal cracks, joints, or other narrow openings
mixture of concentrated refined coal tar emulsion water and
(less than 38.5 mm [1 ⁄2 in.] wide) in pavements against the
sand, with or without an additive, as specified in Specification
entrance or passage of water or other debris.
D6945/D6945M.
3.3.9 crude coal tar—condensed material taken from the
coking process (high-temperature heating of coal under a 5.2 Crack Sealant—As specified by the refined coal tar
emulsion manufacturer.
vacuum) and containing all of the volatile constituents.
3.3.10 cure, final (of the seal coat)—the process of evapo- 5.3 Oil Spot Primer—As specified by the refined coal tar
ration of water and volatiles of the applied seal coating mixture emulsion manufacturer.
over the period of days resulting in the coating reaching its
5.4 Pavement Primer—As specified by the refined coal tar
ultimate strength. The duration of this process is dependent
emulsion manufacturer.
upon ambient conditions.
6. Equipment
3.3.11 cure, initial (of the seal coat)—the condition of an
applied seal coating material that enables it to withstand 6.1 Use application equipment that is capable of applying
the required coating rates evenly over the entire width of the
vehicle traffic without damage to the seal coat.
application mechanism to provide a continuously coated sur-
3.3.12 drying (of the seal coat)—the process of evaporation
face. For spray units, this can be accomplished with either a
of water of the applied seal coating mixture resulting in the
spray bar or a wand-type application device. To ensure this,
coating being able to sustain light foot traffic.
equip all spray units with a pumping distribution system using
3.3.13 mechanized application equipment—equipment used
positive displacement pumps.All squeegee/brush units shall be
to mix and apply the refined coal tar emulsion mixture either
properly adjusted and in condition for application of seal coat
with a spray or squeegee unit.
materials so that there are no streaks in the coating.
3.3.14 priming—application of an initial coat of a material
6.2 Bulk storage tanks shall be capable of mixing or
designed to assist the adhesion of the additional coats of seal
circulating, or both, the coat tar emulsion to a uniform
coating materials. Primers are always used as under coatings
consistency.
and are not designed to be used by themselves.
6.3 The mixing part of the application equipment must be
3.3.15 refined coal tar—a selectively distilled coal tar meet-
tank type with a mechanically powered, full sweep mixer
ing the requirements of Specification D490, grade RT-12.
capable of homogeneously mixing the entire contents of the
3.3.16 refined coal tar emulsion—astableandhomogeneous
tank.
dispersion of refined coal tar, clay, mineral fillers, and specialty
6.4 Use of hand squeegee or brush application will be
chemicals in water.
restricted to places not accessible to mechanized equipment, or
3.3.17 seal coating—process of applying a protective coat- to accommodate neat trim work at curbs and so forth. Material
ing to a bituminous concrete pavement.
that is applied by hand app
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