ASTM C173/C173M-24 PDF

Overview

ASTM C173/C173M-24: Standard Test Method for Air Content of Freshly Mixed Concrete by the Volumetric Method is a globally recognized standard developed by ASTM International. This method specifies procedures for determining the air content of freshly mixed concrete, regardless of aggregate type-dense, cellular, or lightweight. The ASTM volumetric method is especially useful for concretes containing lightweight aggregates, air-cooled slag, and highly porous natural aggregates, as it accurately measures the air contained in the mortar portion without being affected by air trapped within the aggregate particles.

Knowing the air content of concrete is vital for both quality assurance and durability, as it directly impacts concrete workability, freeze-thaw resistance, and overall performance in construction projects.

Key Topics

• Comprehensive Applicability: Suitable for all freshly mixed concretes, including those with lightweight or highly porous aggregates.
• Volumetric Measurement: Utilizes a calibrated air meter, water, and isopropyl alcohol to determine air content based on volume displacement.
• Isopropyl Alcohol Use: The method calls for isopropyl alcohol to minimize foam during testing, ensuring accurate measurements. The quantity used may require correction factors.
• Separate Measurement Systems: The standard supports both SI and inch-pound units but prohibits intermixing of units within a test to avoid non-conformance.
• Quality and Consistency: Offers procedures for sampling, apparatus calibration, and operator precision, which underpin reliable, repeatable results.
• Safety Considerations: Users must observe safety, health, and environmental practices due to hazards associated with fresh cementitious mixtures and isopropyl alcohol.

Applications

This standard test method finds broad application across various aspects of the concrete industry:

• Quality Control at Concrete Plants and Job Sites: Ensures that the concrete delivered and placed meets project specifications for air content, essential for structural integrity and freeze-thaw resistance.
• Assessment of Air-Entraining Admixtures: Verifies the effectiveness of additives used to intentionally introduce air voids into the concrete mix.
• Testing of Specialty and Lightweight Concretes: Offers a reliable solution for evaluating concretes with non-standard aggregate types, such as lightweight aggregate or slag that may influence air measurements made by other methods.
• Compliance and Acceptance Testing: Widely used by contractors, state DOTs, and agencies to certify construction materials meet project standards.
• Field and Laboratory Settings: Method is suitable for use both onsite and under laboratory conditions, ensuring flexibility in testing environments.

Related Standards

Several ASTM standards are referenced and often used in conjunction with ASTM C173/C173M-24:

• ASTM C231 – Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method
• ASTM C138/C138M – Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
• ASTM C143/C143M – Test Method for Slump of Hydraulic-Cement Concrete
• ASTM C172 – Practice for Sampling Freshly Mixed Concrete
• ASTM C1758/C1758M – Practice for Fabricating Test Specimens with Self-Consolidating Concrete
• ASTM C125 – Terminology Relating to Concrete and Concrete Aggregates

Practical Value

Implementing ASTM C173/C173M-24 helps construction professionals reliably control the quality and durability of concrete. Accurate air content determination is crucial for weather-resistant structures and long-lasting performance. This volumetric method is a foundational test for ensuring compliance with modern concrete construction standards, especially for projects utilizing innovative aggregate materials or requiring exceptional durability. The standard’s clear, robust procedures and its acceptance by regulatory authorities make it an essential reference for engineers, technicians, and quality control personnel worldwide.