Meaning and use

ASTM D7735 Type A Hardness Tester for Thermoplastic Pavement Marking at High Temperatures The standard test method for hardness testing covers the Type A hardness tester for thermoplastic pavement marking materials at high temperatures.

5.1 This method is based on the penetration of a specific type of indenter when pressed into the material under specific conditions. Indentation hardness is inversely proportional to the penetration force and depends on the elastic modulus of the material, viscoelastic behavior, the geometry of the indenter, the force applied, and the temperature at the time of testing. The test method is empirical and is therefore primarily used for control purposes. There is no simple relationship between the indentation hardness determined by this test method and any fundamental properties of the material being tested.

ASTM D7735-2017 “Standard Test Method for Hardness Testing with Type A Durometers for Thermoplastic Pavement Markings at High Temperatures”

Step 1: Scope

1.1 This test method covers the Type A durometer hardness of thermoplastic pavement marking materials at high temperatures.

1.2 This test method is similar in hardness to test method D2240, with special attention to keeping the temperature of the test sample and instrument constant. In the world of highway materials, it is sometimes referred to as “anti-indentation”.

1.3 All materials, instruments, or equipment used to determine temperature, hardness, and time shall be traceable to the National Institute of Standards and Technology or other internationally recognized parallel organizations.

1.4 Values expressed in SI units shall be regarded as standard values. The values given in parentheses are for reference only.

1.5 This standard is not intended to address all safety concerns (if any) associated with its use. It is the responsibility of users of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory restrictions prior to use.

1.6 This international standard is based on internationally recognized standardization principles established in the “Decision on Principles for the Development of International Standards, Guidelines and Recommendations” issued by the WTO Committee on Technical Barriers to Trade (TBT).