AASHTO T 348-13 (2018) PDF Download

The AASHTO T 348-13 (2018) standard provides guidelines for determining the air-void characteristics of fresh concrete using a mortar sample. This method involves capturing air bubbles released from a mortar sample to determine the spacing factor, specific surface, and entrained air content of the concrete's air-void system.

It is important to note that the sample collected using this method will only represent the depth of the concrete up to approximately 60 mm (2.5 in.) below the sampling level. Furthermore, this test method is applicable to fresh concrete with a minimum slump of 10 mm (0.4 in.) and an air content ranging from 3.5 to 10 percent by volume. It is also worth mentioning that only air voids smaller than 3 mm (0.1 in.) in diameter can be measured using this method.

To obtain accurate results, the test should be conducted in sheltered and stable conditions.