AASHTO T158

Full Name

AASHTO T158 – Standard Method of Test for Bleeding of Concrete

Scope

AASHTO T158 is a standard test method used to determine the bleeding characteristics of freshly mixed concrete. Bleeding refers to the tendency of water to rise to the surface of concrete due to settlement of heavier solid particles. This phenomenon can lead to issues such as reduced strength, increased permeability, and decreased durability of the concrete.

Key aspects of AASHTO T158:

  • Purpose: the primary objective of this test is to quantify the amount of bleeding water that separates from a concrete sample over a specific time period. This information is crucial for assessing the mix design and its potential impact on the concrete’s properties and performance.
  • Test methods: AASHTO T 158 outlines two test methods for determining bleeding:
    1. Method A: involves minimal vibration of the concrete sample and is typically used for non-air-entrained concrete.
    2. Method B: utilizes more rigorous vibration and is suitable for air-entrained concrete.
  • Procedure: both methods involve filling a cylindrical container with freshly mixed concrete, allowing it to settle, and periodically measuring the amount of bleeding water that accumulates on the surface. The bleeding rate and total bleeding capacity are then calculated based on these measurements.
  • Significance: bleeding can significantly affect the properties of concrete. Excessive bleeding can lead to weakened surface layers, increased porosity, and decreased bond strength between the concrete and reinforcement. By measuring the bleeding characteristics, engineers can optimize the mix design to minimize bleeding and ensure the desired performance and durability of the concrete.

Applications of AASHTO T158:

  • Quality control: concrete producers use this test to ensure that their mixes meet the specified bleeding requirements.
  • Mix design optimization: the results of the bleeding test can be used to adjust the mix design by changing the proportions of water, cement, aggregates, or admixtures to achieve the desired bleeding characteristics.
  • Performance evaluation: the test can also be used to assess the potential impact of bleeding on the performance and durability of concrete in specific applications.

AASHTO T158 Accredited Laboratory

Applied Testing & Geosciences, LLC is accredited for performing tests using the AASHTO T158 standard.

Our laboratory offers comprehensive concrete testing services, including the determination of bleeding characteristics according to AASHTO T158. Our experienced technicians utilize standardized procedures and equipment to ensure the accuracy and reliability of our test results.

Contact us for more information.

Resources

Keywords

bleeding; concrete; freshly mixed concrete; bleeding rate; bleeding capacity; settlement; water; aggregate; cement; admixture

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