Comparing ASTM and AASHTO Standards in Construction Materials Testing

July 12, 2024

In the construction materials testing world, it is important to follow standards to ensure the quality, safety, and performance of materials used in construction projects. The two most prominent organizations that establish these standards are the American Society for Testing and Materials (ASTM) and the American Association of State Highway and Transportation Officials (AASHTO). While both organizations seek to standardize testing methods, their target areas and methodologies sometimes differ. Let us compare these two standards from the perspective of a construction materials lab.

Overview of ASTM and AASHTO

ASTM (American Society for Testing and Materials):

Founded in 1898.
Scope: Develops standards for a wide range of materials, products, systems, and services.
Broad focus across industries such as construction, petroleum, and chemicals.
Membership is open to individuals and organizations from the United States and throughout the world.

AASHTO (American Association of State Highway and Transportation Officials):

Founded in 1914.
Scope: Develops standards for highway and transportation infrastructure.
Focus on roads, bridges, and related facilities.
Membership is limited to the Departments of Transportation from each state in the United States and its territories.

Key Differences in Standards

1. Focus Areas:

ASTM: Standards apply beyond construction to include metals, plastics, textiles, and consumer products. While ASTM standards started in the United States, they are adopted globally across various industries.
AASHTO: Focuses on materials and procedures related to all modes of transportation: air, highways, public transportation, active transportation, rail, and water. This includes requirements for asphalt, concrete, aggregates, and geotechnical materials used in road and bridge construction.

2. Development Process:

ASTM: Standards are established by a consensus process involving a diverse group of stakeholders, including manufacturers, users, government officials, and academics. This method is intended to assure widespread acceptance and applicability.
AASHTO: Standards are developed by committees comprising officials from various state Departments of Transportation. The goal is to create guidelines that address the specific requirements of state and local transportation departments.

3. Testing Procedures:

ASTM: Provides detailed steps and procedures for testing a wide range of materials. ASTM standards may include more than one method for testing the same property, allowing labs to select the one that best meets their requirements.
AASHTO: Provides detailed steps and procedures tailored to transportation materials. The primary focus is on methods that are applicable in the field of transportation engineering.

4. Updates:

ASTM: Regularly updates its standards to reflect new research, technology advancements, and industry practices. Each standard is reviewed at least once every five years and removed from publication if not updated or reapproved after eight years.
AASHTO: Regularly updates its standards, focusing more on meeting the practical needs and experiences of the various state Departments of Transportation.

5. Acceptance:

ASTM: Worldwide acceptance and application across different industries. ASTM standards are often referenced in international trade and regulations framework.
AASHTO: Mainly used by state and local transportation departments within the United States and its territories. There are times however, the AASHTO standards could influence international projects involving American companies.

Implications to Construction Materials Testing (CMT) Laboratories

For Constructions Materials Testing (CMT) firms that perform and manage Quality Assurance (QA) and Quality Control (QC) processes, understanding the similarities and differences between ASTM and AASHTO standards are important for the following reasons:

Client Requirements: CMT labs must have the equipment and resources to conduct tests based on what their clients request. Depending on the nature of the project, end client and location, it could be either ASTM or AASHTO standards.
Accreditation: CMT labs typically seek accreditation from the applicable accreditation bodies such as Construction Materials Engineering Council (CMEC) and AASHTO Accreditation Program (AAP). Therefore, they need to demonstrate their proficiency in the respective ASTM and AASHTO standards.
Equipment and Training: Different standards may have different requirements in terms of testing equipment and procedures. As such, CMT labs need to invest in the right equipment and training to ensure that their technicians are trained to perform CMT tests that conform to both ASTM and AASHTO standards.
Reporting: Understanding the subtle differences between ASTM and AASHTO standards ensures that CMT labs can analyze and report test results in a way that conforms to the corresponding standards.

Conclusion

While both ASTM and AASHTO play important roles in standardizing construction materials testing, their focus areas and techniques differ. Understanding these distinctions allows CMT labs to better serve their clients, comply with appropriate regulations, and contribute to the overall quality and safety of construction projects. Having the correct construction materials testing software such as eFieldData makes it easy to produce reports that meet the standards, assuring uniformity and accuracy in reporting. An efficient software would also help CMT labs keep track of technicians' training and equipment maintenance, further enhancing the reliability and quality of their testing processes.

Please visit the official ASTM and AASHTO websites for more details on the specific standards.