ASTM C40

Full Name

ASTM C40 – Standard Test Method for Organic Impurities in Fine Aggregates for Concrete

Scope

ASTM C40 outlines the procedure to determine the presence of potentially harmful organic impurities in fine aggregates intended for use in concrete.

The scope includes:

  • Purpose: to provide a preliminary assessment of the acceptability of fine aggregates regarding organic impurities, as required by ASTM C33 (Standard Specification for Concrete Aggregates).
  • Method – two procedures are provided:
    1. Comparison with a standard color solution.
    2. Comparison with a glass color standard.
  • Applicability: Fine aggregates to be used in hydraulic cement mortar or concrete.

Limitations:

  • The test is a qualitative indicator, not a quantitative measurement.
  • It doesn’t identify the specific types of organic impurities present.

Further testing (such as ASTM C87) may be necessary to determine the actual impact of organic impurities on concrete strength.

The primary value of ASTM C40 lies in providing a warning sign if potentially harmful organic impurities are present. If a sample shows a darker color than the standard, further testing is recommended to evaluate the potential impact on concrete performance.

By identifying organic impurities early on, ASTM C40 helps to:

  • Mitigate the risk of strength loss: early detection allows for corrective actions, such as using alternative aggregates or employing concrete mix designs that can mitigate the effects of organic impurities.
  • Ensure long-term performance: concrete free from harmful organic materials is less susceptible to cracking and deterioration over time.
  • Promote quality control: regular testing using ASTM C40 helps maintain consistent concrete quality throughout the construction project.

ASTM C40 Accredited Laboratory

Applied Testing & Geosciences, LLC is accredited for performing tests using the ASTM C40 standard.

Our laboratory offers ASTM C40 testing services to help you safeguard your project from the unseen threats posed by organic impurities in fine aggregates. Contact us today to discuss how we can ensure your concrete meets the highest quality standards.

Resources

Keywords

organic impurities; fine aggregates; color comparison; sodium hydroxide solution; glass color standard

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