APTTS stands for Asphalt Pavement Thermal Testing System.

The OEM-Cooper Thermal Stress Restrained Specimen Test (TSRST) is used to determine the low-temperature cracking susceptibility of asphalt concrete. In the early 1990s the TSRST was developed by OEM with Oregon State University (OSU) as part of the Strategic Highway Research Program in the USA. The test method became AASHTO TP10.

More recently the TSRST test has been included as one of the tests within prEN12697-46. OEM-Cooper have developed the TSRST to perform tests included in this standard. Now as a multipurpose low temperature testing machine the TSRST has been renamed the Asphalt Pavement Thermal Testing System (APTTS)
With over 20 years of experience, and as the original developers of the TSRST OEM-Cooper are the recognised word experts in the field.