ASTM D7538-09(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: D7538 − 09 (Reapproved 2023)
Standard Practice for
Evaluating the Water Wash-Off Resistance of Traffic Paints
Using an Atomizing Spray Device
This standard is issued under the fixed designation D7538; 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 D711 Test Method for No-Pick-Up Time of Pavement Mark-
ings
1.1 A newly applied traffic paint film may be exposed to rain
D823 Practices for Producing Films of Uniform Thickness
of varying intensities shortly after application. Practice D7377
of Paint, Coatings and Related Products on Test Panels
describes a practice for evaluating the water wash-off resis-
D1005 Test Method for Measurement of Dry-Film Thick-
tance of traffic paints to a hard rain using a steady stream of
ness of Organic Coatings Using Micrometers
water from a faucet at a rate of approximately 5.7 L per min.
D1212 Test Methods for Measurement of Wet Film Thick-
Practice D7538 is a similar practice that describes the use of an
ness of Organic Coatings
adjustable nozzle atomizing spray device to deliver a spray of
D3924 Specification for Standard Environment for Condi-
water that simulates rain rates from approximately 0.05 L to
tioning and Testing Paint, Varnish, Lacquer, and Related
0.5 L per min. This test can be used to compare conventional
Materials
and fast-dry traffic paints for their relative ability to withstand
D4414 Practice for Measurement of Wet Film Thickness by
rain soon after application on roadway surfaces.
Notch Gages
1.2 The values stated in SI units are to be regarded as
D7377 Practice for Evaluating the Water Wash-Off Resis-
standard. No other units of measurement are included in this
tance of Traffic Paints using a Water Faucet
standard.
1.3 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Definitions:
responsibility of the user of this standard to establish appro-
3.1.1 conventional waterborne traffıc paint, n—an aqueous
priate safety, health, and environmental practices and deter-
traffic paint that uses a conventional-dry latex binder.
mine the applicability of regulatory limitations prior to use.
3.1.1.1 Discussion—Typical no-pick-up dry times, as pre-
1.4 This international standard was developed in accor-
scribed in Test Method D711, for conventional traffic paints are
dance with internationally recognized principles on standard-
20 min to 45 min.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 3.1.2 durable fast-dry waterborne traffıc paint, n—an aque-
mendations issued by the World Trade Organization Technical ous traffic paint that uses a third generation durable fast-dry
Barriers to Trade (TBT) Committee. latex binder.
3.1.2.1 Discussion—Air or airless spray application on
2. Referenced Documents
roadways is typically 0.64 mm wet or about 0.39 mm dry. The
range of application for durable waterborne paints is 0.56 mm
2.1 ASTM Standards:
to 0.89 mm wet, but sometimes the durable paints are also
D562 Test Method for Consistency of Paints Measuring
striped at standard line thickness.
Krebs Unit (KU) Viscosity Using a Stormer-Type Viscom-
eter
3.1.3 fast-dry waterborne traffıc paint, n—an aqueous traffic
paint that uses a fast-dry traffic latex binder.
3.1.3.1 Discussion—Typical no-pick-up dry times, as pre-
This practice is under the jurisdiction of ASTM Committee D01 on Paint and
scribed in Test Method D711, for fast-dry traffic paints are <10
Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.44 on Traffic Coatings.
min.
Current edition approved Dec. 1, 2023. Published January 2024. Originally
3.1.4 standard line fast-dry waterborne traffıc paint, n—an
approved in 2009. Last previous edition approved in 2018 as D7538 – 09 (2018).
DOI: 10.1520/D7538-09R23.
aqueous traffic paint that uses a first or second generation
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
fast-dry latex binder.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
3.1.4.1 Discussion—Air or airless spray application on
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. roadways is typically 0.38 mm wet or about 0.23 mm dry.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7538 − 09 (2023)
3.1.5 waterborne traffıc paint, n—an aqueous traffic paint 7. Reagents
(usually white or yellow) containing either a conventional or
7.1 Tap Water—to partially fill the sprayer container.
fast-dry latex binder.
7.2 Acetone—to clean glass plates prior to paint application
3.1.6 water wash-off, n—the erosion or removal of freshly
(not needed for draw-down charts since they are not reused.)
applied traffic paint in the field by rain or in the laboratory
using simulated rain.
8. Procedure
3.1.6.1 Discussion—Sometimes referred to as water wash-
8.1 Paint Consistency:
out.
8.1.1 Determine the Krebs (KU) viscosity of the paint in
accordance with Test Method D562 using a paddle-type
4. Summary of Practice
viscometer as prescribed by Test Method D562. This determi-
4.1 This practice involves preparing a series of uniform
nation is optional but can be important since the dry time of the
thickness films of traffic paint on standard substrates. The films
traffic paint and water-wash off performance can be affected by
are allowed to dry over different time periods in a conditioned
the paint viscosity.
environment, and then each paint film is subsequently sub-
jected to a water spray. Films are wash-off resistant when no 8.2 Calibration of Atomizing Spray Devices:
8.2.1 Partially fill the finger pumped, adjustable nozzle
paint is removed by the water spray.
spray bottle or adjustable nozzle garden-type sprayer with at
5. Significance and Use
least 250 mL of clean tap water and allow to equilibrate to
5.1 After waterborne traffic paints are applied to a road
room temperature.
pavement, it is important that the
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