ASTM C661-06

Standard Test Method for Indentation Hardness of Elastomeric-Type Sealants by Means of a Durometer

SIGNIFICANCE AND USE
The results obtained by this test method are simply a measure of the indentation into the sealant material of the indentor under load; they are not generally considered a measure of abrasion or wear resistance of the sealant.
SCOPE
1.1 This test method describes a laboratory procedure for determining indentation hardness of joint sealing compounds, (single- and multicomponent), intended for use in building construction.  
1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.  
1.3 This standard does not purport to address the safety problems 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: 31-Dec-2005
• ICS: 83.060 - Rubber
• ICS: 91.100.50 - Binders. Sealing materials
• Technical Committee: C24 - Building Seals and Sealants
• Drafting Committee: C24.20 - General Test Methods

Relations

• Replaces: ASTM C661-98 - Standard Test Method for Indentation Hardness of Elastomeric-Type Sealants by Means of a Durometer
• Effective Date: 01-Jan-2006
• Replaced By: ASTM C661-06(2011) - Standard Test Method for Indentation Hardness of Elastomeric-Type Sealants by Means of a Durometer
• Effective Date: 01-Jan-2011
• Referred By: ASTM C1311-22 - Standard Specification for Solvent Release Sealants
• Effective Date: 01-Jan-2006
• Referred By: ASTM C920-18 - Standard Specification for Elastomeric Joint Sealants
• Effective Date: 01-Jan-2006
• Referred By: ASTM D5893/D5893M-16(2021) - Standard Specification for Cold-Applied, Single-Component, Chemically Curing Silicone Joint Sealant for Portland Cement Concrete Pavements
• Effective Date: 01-Jan-2006
• Referred By: ASTM C1184-23 - Standard Specification for Structural Silicone Sealants
• Effective Date: 01-Jan-2006
• Referred By: ASTM C1021-08(2023) - Standard Practice for Laboratories Engaged in Testing of Building Sealants
• Effective Date: 01-Jan-2006
• Referred By: ASTM C1369-19 - Standard Specification for Secondary Edge Sealants for Structurally Glazed Insulating Glass Units
• Effective Date: 01-Jan-2006
• Referred By: ASTM C1193-16(2023) - Standard Guide for Use of Joint Sealants
• Effective Date: 01-Jan-2006

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
Designation:C661–06
Standard Test Method for
Indentation Hardness of Elastomeric-Type Sealants by
1
Means of a Durometer
This standard is issued under the fixed designation C661; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope indentor under load; they are not generally considered a
measure of abrasion or wear resistance of the sealant.
1.1 This test method describes a laboratory procedure for
determining indentation hardness of joint sealing compounds,
5. Apparatus
(single- and multicomponent), intended for use in building
5.1 Durometer, Type A-2, with a dial graduated in units from
construction.
0 to 100. (See Test Method D2240 for a description of the
1.2 The values stated in SI units are to be regarded as the
indentor and a method of calibration of the durometer.)
standard. The values in parentheses are for information only.
5.2 Rectangular Brass Frame, with inside dimensions 130
1.3 Thecommitteewithjurisdictionoverthisstandardisnot
1 1
by 40 by 6 mm (approximately 5 by 1 ⁄2 by ⁄4 in.).
aware of any comparable standards published by other orga-
5.3 Aluminum Plates, two 16 to 24 gage, 80 by 150 mm
nizations.
(approximately 3 by 6 in.).
1.4 This standard does not purport to address the safety
5.4 Thin-Bladed Knife.
concerns, if any, associated with its use. It is the responsibility
5.5 Chamber, capable of maintaining 38 6 2°C (100 6
of the user of this standard to establish appropriate safety and
3.5°F) and 95 % relative humidity.
health practices and determine the applicability of regulatory
5.6 Metal Straightedge.
limitations prior to use.
6. Standard Test Conditions
2. Referenced Documents
2 6.1 Unless otherwise specified by those authorizing the
2.1 ASTM Standards:
tests, standard conditions for test are room temperature: 23 6
C717 Terminology of Building Seals and Sealants
2°C (73.4 6 3.6°F) and 50 6 5 % relative humidity.
D2240 Test Method for Rubber Property—Durometer
Hardness
7. Procedure
3. Terminology 7.1 Test for Hardness of Multicomponent Sealants:
7.1.1 Condition at least 250 g of base compound and
3.1 Definitions—See Terminology C717 for applicable defi-
appropriate amounts of curing agent for at least 24 h at
nitions of the following terms: compound; elastomeric; hard-
standard conditions; then mix the components thoroughly for 5
ness; joint; sealant, non-sag; sealant, self-levling.
min.
4. Significance and Use 7.1.2 Fill the brass frame, after centering it on the aluminum
plate, with a portion of the conditioned compound and strike it
4.1 The results obtained by this test method are simply a
off flat with a metal straightedge. Lift the frame from the
measure of the indentation into the sealant material of the
sealant after separating it by running a thin-bladed knife along
the inside of the frame. Prepare two such specimens and cure
them for 14 days at standard conditions.
1
ThistestmethodisunderthejurisdictionofASTMCommitteeC24onBuilding
Seals and Sealants and is the direct responsibility of Subcommittee C24.20 on
NOTE 1—In the case of a self-leveling sealant or compound, do not lift
General Test Methods.
the brass frame until the sealant is sufficiently cured so that it will not
Current edition approved Jan. 1, 2006. Published February 2006. Originally
spread on the plate.
approved in 1970. Last previous edition approved in 1998 as C661 – 98. DOI:
10.1520/C0661-06.
7.1.3 At the end of the curing period, take three hardness
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
readings on each specimen at standard conditions. Hold the
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
durometer on the surface of the specimen and press it firmly
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. against the surface using a force of about 1.3 kgf (3 lbf). Keep
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C661–06
the pressure foot parallel to the surface of the specimen. Take 7.2.2 Center the brass frame on the aluminum plate and fill
the instantaneous indentation reading immediately after mak- the opening with a portion of the conditioned compound,
ing firm contact between the pressure foot and the specimen. striking the compound off flat with a straightedge. Lift the
After taking the first reading, shift the durometer (or specimen) frame from the sealant after separating it by runnin
...