AASHTO T161

Full Name

AASHTO T161 – Standard Method of Test for Resistance of Concrete to Rapid Freezing and Thawing

Scope

AASHTO T161 is a standard test method used to evaluate the durability of concrete when subjected to rapid and repeated cycles of freezing and thawing. This test is crucial for assessing the ability of concrete to withstand harsh environmental conditions, particularly in regions with cold climates where freeze-thaw cycles are common. The freeze-thaw resistance of concrete is a critical factor in determining its long-term performance and service life in various applications, such as pavements, bridges, and other exposed structures.

Key aspects of AASHTO T161:

  • Test principle: the test involves subjecting prepared concrete specimens to controlled cycles of freezing and thawing in a laboratory environment. The specimens are typically prisms or cylinders that are partially submerged in water or a specified solution. The freezing and thawing cycles are accelerated compared to natural conditions to expedite the test.
  • Evaluation: the durability of the concrete is assessed by monitoring its performance throughout the test. The most common parameters monitored are the relative dynamic modulus of elasticity (RDME) and the mass loss of the specimens. The RDME is a measure of the stiffness of the concrete, and a decrease in RDME indicates a loss of structural integrity due to freeze-thaw damage. Mass loss is another indicator of damage, as the concrete may lose material due to scaling or cracking.
  • Test procedures – AASHTO T161 outlines two procedures:
    1. Procedure A – rapid freezing and thawing in water: the specimens are completely submerged in water during the freezing and thawing cycles.
    2. Procedure B – rapid freezing in air and thawing in water: the specimens are frozen in air and then thawed in water. This procedure simulates the conditions experienced by concrete pavements exposed to deicing salts.

Significance of AASHTO T161:

  • Durability assessment: the freeze-thaw test is a fundamental tool for evaluating the durability of concrete, particularly its resistance to freeze-thaw damage. This information is crucial for selecting suitable concrete mixtures for specific applications and environmental conditions.
  • Mix design optimization: by conducting freeze-thaw tests on different concrete mixtures, engineers can optimize the mix design to achieve the desired level of freeze-thaw resistance. This may involve adjusting the water-cement ratio, using air-entraining admixtures, or selecting aggregates with good freeze-thaw resistance.
  • Quality control: AASHTO T161 provides a standardized test method for assessing freeze-thaw resistance, ensuring consistency and reliability in the evaluation of concrete across different laboratories and projects.

AASHTO T161 Accredited Laboratory

Applied Testing & Geosciences, LLC is accredited for performing tests using the AASHTO T161 standard.

Our laboratory offers comprehensive concrete testing services, including the assessment of freeze-thaw resistance according to AASHTO T161. Our experienced technicians utilize state-of-the-art equipment and adhere to strict quality control procedures to provide accurate and reliable test results for your construction projects.

Contact us for more information.

Resources

Keywords

concrete; freeze-thaw; durability; scaling; relative dynamic modulus of elasticity; mass loss; air entrainment; deicer salt; scaling resistance

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