AASHTO TP 114-18 (2019) PDF Download

AASHTO TP 114-18 is a provisional standard method of test that is used to determine the interlayer shear strength (ISS) of asphalt pavement layers. This test can be conducted on samples that are either laboratory-prepared or taken from existing core samples.

The test can be performed on asphalt pavement samples that have a diameter of either 150 mm (6 in.) or 100 mm (4 in.). The standard specifies that the test is applicable when the asphalt overlay layer and the base layer are both 50 ± 5 mm (2.0 ± 0.2 in.) thick, and the total specimen thickness does not exceed 150 mm (6 in.). It is also recommended to saw cut the layers of the specimen to the specified thickness.

The main objective of this test is to determine the interlayer shear strength, which is the ability of the asphalt pavement layers to resist shearing forces between them. This information is crucial for assessing the performance and integrity of the pavement structure.