ASTM C226
Understanding ASTM C2262 Standard Specification for Air-Entraining Additions for Use in the Manufacture of Air-Entraining Hydraulic Cement
ASTM C226 is a comprehensive standard covering the specification for air-entraining additions used in the manufacture of air-entraining hydraulic cement. This standard is essential for ensuring the quality and performance of air-entraining hydraulic cements, which are crucial in various construction applications, especially where freeze-thaw durability and workability are significant concerns.
KEY ASPECTS OF ASTM C226
Scope and Purpose:
Specifies requirements for materials used as air-entraining additions in air-entraining hydraulic cement.
Covers test methods to establish the suitability of these additions.
Intended for use in cements conforming to Specifications C 150, C 595, and C 1157.
Referenced Documents:
Includes references to other ASTM standards like C 33 (Concrete Aggregates), C 39/C 39M (Compressive Strength of Cylindrical Concrete Specimens), C 114 (Chemical Analysis of Hydraulic Cement), and many others.
Materials and Testing:
Details on the types of cements to be tested, including requirements for the control cement and the one containing the proposed addition.
Specifies the fineness, chemical composition, and other necessary properties of the cement.
Includes guidelines for preparing and testing aggregates used in the tests.
General Requirements:
Sets forth the requirements for air-entraining additions, including their effects on setting time, compressive strength, autoclave expansion, and air content.
Specifies that the addition, when used in cement, should not significantly alter the cement's fundamental properties.
Sampling and Test Methods:
Outlines the procedures for sampling cement during grinding.
Chemical Analysis of Cement: Use Test Methods C 114.
Determination of Addition in Finished Cement:
Measure the percentage of the addition in the finished cement.
Use the method provided by the manufacturer or seller of the proposed addition.
Ensure the method is suitable for both qualitative and quantitative assessment.
Fully describe the method in the test report.
Fineness of Cement: Apply Test Method C 115 or C 204.
Normal Consistency: Utilize Test Method C 187.
Time of Setting:
Assess using the Vicat needle as per Test Method C 191.
Autoclave Expansion: Follow Test Method C 151.
Air Content of Mortar: Use Test Method C 185.
Compressive Strength of Mortar: Conduct testing with Test Method C 109/C 109M.
Length Change of Mortar:
Determine the length change of mortar bars as per Test Method C 596.
After demolding, cure the specimens in saturated lime water for 6 days (total age of 7 days).
Measure the length of each specimen at 7, 28, 180, and 365 days of age.
Record the length change for each bar as a percentage of its length at 7 days of age.
Concrete Mixtures and Testing:
Details on the preparation of concrete mixtures for testing, including proportions, mixing, and adjustment of water content.
Specifies the tests to be conducted on plastic concrete, including consistency, unit weight, and air content tests.
Hardened Concrete Testing:
Describes the types and numbers of specimens to be made for different tests.
Includes methods for testing compressive strength, flexural strength, and resistance to freezing and thawing.
Reporting:
Requires a detailed report including information about the material, the results of analyses and tests, and a statement regarding the evaluation's scope.
IMPORTANCE IN CONSTRUCTION
ASTM C226 plays a crucial role in the construction industry by ensuring that air-entraining additions meet specific quality standards, thereby ensuring the durability and workability of the resulting air-entraining hydraulic cement. These standards help in mitigating risks associated with freeze-thaw cycles and enhancing the longevity of concrete structures.
COMPLIANCE AND SAFETY
Compliance with ASTM C226 ensures that the air-entraining additions used in cements are safe, reliable, and effective. The standard also cautions about the safety concerns related to handling cement and the additives, underlining the importance of appropriate safety and health practices in construction material manufacturing and testing.