ASTM C87/C87M-23 PDF

Overview

ASTM C87/C87M-23: Standard Test Method for Effect of Organic Impurities in Fine Aggregate on Strength of Mortar is a leading standard developed by ASTM International. This test method is used to assess the impact of organic impurities found in fine aggregate (such as sand) on the compressive strength of mortar. Determining the presence and effect of organic impurities is crucial to ensuring the quality and performance of construction materials, particularly in applications where mortar strength is a critical factor. This standard supports compliance with Specification ASTM C33/C33M regarding organic impurities in fine aggregate.

Key Topics

• Purpose of the Standard
  • Evaluates the effect of organic impurities in fine aggregate on mortar strength.
  • Used as a final determination for the acceptability of aggregates that initially fail colorimetric tests for organic content.
• Scope of Applicability
  • Samples tested by ASTM C40/C40M that show a supernatant color darker than the standard require further evaluation by this method.
  • Compares compressive strength of mortar made with both washed and unwashed fine aggregates.
• Test Method Summary
  • Mortar cubes are prepared using both types of aggregates.
  • After a specified curing period, the compressive strengths of both sets of cubes are measured and compared.
• Measurement Units
  • Procedures and reporting can use either SI units or inch-pound units, but not a combination of both.
• Safety Considerations
  • The standard reminds users to adopt appropriate safety and environmental practices, as fresh hydraulic cement mixtures can be caustic.

Applications

The ASTM C87/C87M-23 test method is widely applied in the construction and materials testing industries to:

• Assess Aggregate Quality
  • It is a critical part of quality control in ready-mix concrete, masonry mortar, and pre-cast concrete operations to ensure aggregates meet stringent organic impurity requirements.
• Acceptance Testing
  • Frequently used by laboratories, contractors, and engineers when fine aggregate samples fail ASTM C40/C40M color tests. If mortar cube strengths from unwashed aggregates are comparable to those from washed samples, the material may still be deemed acceptable for use.
• Specification Compliance
  • Facilitates compliance with ASTM C33/C33M by providing a reliable method to evaluate and report on the presence and impact of organic impurities.
• Supporting Construction Safety and Durability
  • Ensures that construction materials will not suffer reduced performance or durability due to organic contaminants in the aggregate.

Related Standards

To ensure accurate and comprehensive testing, ASTM C87/C87M-23 makes reference to several other important standards, including:

• ASTM C33/C33M - Specification for Concrete Aggregates
• ASTM C40/C40M - Test Method for Organic Impurities in Fine Aggregates for Concrete
• ASTM C109/C109M - Test Method for Compressive Strength of Hydraulic Cement Mortars
• ASTM C136/C136M - Test Method for Sieve Analysis of Fine and Coarse Aggregates
• ASTM C150/C150M - Specification for Portland Cement
• ASTM C305 - Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars
• ASTM D75/D75M, D3665, and C702/C702M - Practices for Sampling and Reducing Aggregates to Testing Size

Practical Value

By following ASTM C87/C87M-23, laboratories and construction professionals can ensure their fine aggregates are free from harmful levels of organic impurities that may compromise mortar or concrete strength. The method offers a robust protocol for final acceptability decisions, contributing to higher quality, safer, and more durable concrete structures. Adherence to this standard mitigates the risk of construction material failure due to undetected organic contaminants, ultimately supporting long-term infrastructure performance and compliance with industry best practices.