AASHTO T255
Full Name
AASHTO T255 – Standard Method of Test for Total Evaporable Moisture Content of Aggregate by Drying
Scope
AASHTO T255 is a standard test method used to determine the total evaporable moisture content of aggregate samples. This test is essential for quality control in construction projects, as the moisture content of aggregates can significantly affect the properties of concrete and asphalt mixtures, influencing their workability, strength, and durability.
Key aspects of AASHTO T255:
- Purpose: the primary objective of this test is to quantify the amount of moisture present in an aggregate sample that can be removed by drying. This moisture content is expressed as a percentage of the dry mass of the aggregate.
- Principle: the test involves drying a known mass of the aggregate sample to a constant mass and then calculating the difference between the initial wet mass and the final dry mass. This difference represents the mass of water evaporated during drying, which is then used to calculate the moisture content.
- Equipment: the standard specifies the use of a drying oven, balance, sample containers, and other necessary equipment for conducting the test. It also provides guidelines for selecting the appropriate drying temperature and duration based on the type of aggregate being tested.
- Procedure: the test procedure involves the following steps:
- Weighing a representative sample of the aggregate.
- Drying the sample in an oven at a specified temperature until a constant mass is achieved.
- Weighing the dried sample.
- Calculating the moisture content as a percentage of the dry mass.
Significance of AASHTO T255:
- Mix design: the moisture content of aggregates is a crucial parameter in mix design calculations for concrete and asphalt mixtures. It influences the amount of water and binder required to achieve the desired workability and strength.
- Quality control: by measuring the moisture content of aggregates, construction professionals can ensure that the materials meet the specified requirements and quality standards. Excessive moisture can lead to problems such as reduced strength and increased shrinkage in concrete, while insufficient moisture can affect the compaction and stability of asphalt pavements.
- Field adjustments: the moisture content of aggregates can vary due to environmental conditions. By testing the moisture content on-site, contractors can make necessary adjustments to the mix design or compaction procedures to ensure optimal performance of the construction materials.
AASHTO T255 Accredited Laboratory
Applied Testing & Geosciences, LLC is accredited for performing tests using the AASHTO T255 standard.
Our laboratory offers comprehensive aggregate testing services, including the determination of moisture content according to AASHTO T255. Our experienced technicians utilize calibrated equipment and adhere to strict quality control procedures to provide accurate and reliable results for your construction projects.
Contact us for more information.
Resources
Keywords
moisture content; aggregate; drying; oven drying; mass; sample; container; balance; temperature