ASTM D4799

ASTM D4799 testing is now offered by Micom as part of its UV testing and material testing services. ASTM D4799 —Accelerated weathering test conditions and procedures for bituminous materials (fluorescent UV, water spray, and condensation method)—describes the procedure and the test conditions required for the assessment of the weathering characteristic of bituminous roofing and waterproofing materials. This standard uses UVA lamps as an illuminating source, and it is thus based on the ASTM G154 and the ISO 4892-3 practices.

Accelerated weathering for bituminous materials—use and factor to consider:

The purpose of ASTM D4799 is to provide the test conditions and the procedure that are required for an accelerated weathering test of bituminous substances. This kind of test consists on exposing the specimen to a structured cycle of heat, UV light and moisture exposure as a means to induce an accelerated aging of a sample inside an apparatus in order to characterize the aging properties of the studied compound. It is important to mention that it is impossible to establish an unequivocal correlation between the natural and the accelerated weathering for this method. Indeed, this is due to the fact that there are discrepancies in the atmospheric conditions between the laboratory and the outside environment and thus affect the aging rate. However, it is possible to compare the relative weathering performance of a bitumen material in regard to a control material with known outdoor weathering characteristics. Lastly, in order to assess the changes in attributes, it is necessary to utilize other methods in conjuncture with this exposure.

The main factor that has to be considered when running this test is: the time of exposure.

Typical Experimental parameters for ASTM D4799 testing:

The number of samples required is three when this test is executed in conjuncture with a non-destructive test protocol, but if the following method is destructive, the number of specimens needed is six. The size of the sample is 3 by 6 in (75 by 150 mm) and a control specimen has to be tested alongside the sample. The specifications of the test cycles are listed in table 1, and the experiment parameters are detailed in table 2.

Table I: Typical test cycles parameters

Test cyclesSpecifications
Cycle A4h UV exposure at 60 ± 2.5 °C
4h condensation at 50 ± 2.5 °C
Cycle B20h UV exposure at 60 ± 2.5 °C
4h condensation at 50 ± 2.5 °C
Cycle C20h UV exposure at 80 ± 2.5 °C
4h condensation at 50 ± 2.5 °C
Cycle D4h UV exposure at 60 ± 2.5 °C
15 mins water spray
3.75h condensation at 50 ± 2.5 °C
Cycle E20h UV exposure at 60 ± 2.5 °C
15 mins water spray
3.75h condensation at 50 ± 2.5 °C
Cycle F20h UV exposure at 80 ± 2.5 °C
15 mins water spray
3.75h condensation at 50 ± 2.5 °C

Table II: Typical test parameters

ParametersSpecifications
Lamp typeUVA-340
Irradiance level0.89 ± 0.02 W/(m2nm) at 340 nm
Exposure timeHas to be specified

If you have any questions about the ASTM D4799 test, we invite you to contact our material testing lab today. It will be our pleasure to answer your questions and help you with your custom material testing requirements.

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