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AASHTO M302 – Standard Specification for Slag Cement for Use in Concrete and Mortars


AASHTO M302 is a standard specification that outlines the requirements for slag cement used as a cementitious material in concrete and mortar. Slag cement is a byproduct of iron and steel manufacturing, consisting of granulated blast furnace slag that is ground to a fine powder. This material possesses cementitious properties similar to Portland cement and can be used as a partial replacement for Portland cement or as a separate ingredient in concrete and mortar mixtures.

Key aspects of AASHTO M302:

  • Composition and properties: the standard specifies the physical and chemical requirements for slag cement, including fineness, specific gravity, chemical composition, and hydraulic activity. These requirements ensure that the slag cement meets the desired performance criteria for various applications.
  • Performance requirements: AASHTO M302 outlines the performance requirements for concrete and mortar containing slag cement, including compressive strength, setting time, and air content. These requirements ensure that the concrete or mortar meets the desired strength, durability, and workability characteristics.
  • Testing methods: the standard provides standardized test procedures for evaluating the properties and performance of slag cement, ensuring consistency and reliability in quality control.
  • Applications – slag cement is used in various applications, including:
    • Blended cement: it is commonly blended with Portland cement to produce blended hydraulic cements, such as Type IS (Portland blast-furnace slag cement), which offers improved durability, reduced permeability, and lower heat of hydration compared to ordinary Portland cement.
    • Concrete and mortar: slag cement can be used as a separate ingredient in concrete and mortar mixtures to enhance their properties, such as increased strength, improved workability, and reduced permeability.

Significance of AASHTO M302:

  • Sustainability: utilizing slag cement as a supplementary cementitious material promotes sustainable construction practices by reducing the demand for Portland cement and utilizing industrial byproducts.
  • Enhanced durability: slag cement contributes to the long-term durability of concrete structures by improving their resistance to chemical attack, sulfate attack, and alkali-silica reaction (ASR).
  • Economic benefits: the use of slag cement can lead to cost savings due to its lower cost compared to Portland cement and its potential to reduce the amount of cement required in a concrete mix.

AASHTO M302 Accredited Laboratory

Applied Testing & Geosciences, LLC is accredited for performing tests using the AASHTO M302 standard.

Our laboratory offers comprehensive testing services for slag cement based on AASHTO M302 and other relevant standards. Our experienced technicians conduct a variety of tests to evaluate the physical and chemical properties of your slag cement, ensuring that it meets the specified requirements and contributes to the success of your construction projects.

Contact us for more information.



slag cement; concrete; mortar; portland cement; blended cement; cementitious material; blast furnace slag; granulated slag; compressive strength; setting time; fineness; specific gravity; chemical composition; hydraulic activity