Test Methods describe equipment and procedures used to determine and report a products properties or condition.
iStock.com Test Methods describe equipment and procedures used to determine and report a products properties or condition.

Most concrete contractors are aware that ASTM standards exist. You’ve likely noted references to particular standards in project specifications and seen literature affirming that a product meets ASTM requirements. In the concrete construction industry, it’s mainly product manufacturers and ready-mix suppliers who are charged with meeting ASTM standards. Construction practices (and therefore contractors) are governed more by American Concrete Institute (ACI), Farmington Hills, Mich., codes and requirements. This separation results from a long-standing agreement between the two organizations. Even so, contractors who understand how ASTM standards are developed and applied can benefit. It can help them run their jobs more smoothly, avoid disputes in many cases, and resolve disputes more quickly when they occur.

What is ASTM?

ASTM International, West Conshohocken, Pa., established in 1989 and formerly known as the American Society for Testing and Materials, develops voluntary standards for a broad range of areas, encompassing construction materials, petroleum, textiles, consumer products, electronics, and much more. Its members include about 30,000 technical experts from 135 countries, who serve on one or more of its 141 technical committees. The organization publishes about 12,000 standards each year, which can be found in the 80-volume Annual Book of ASTM Standards or online at its website www.astm.org. The organization also disseminates technical standards information by producing specialized publications, such as journals, manuals, and monographs, and by offering continuing education and training programs.

ASTM members, who represent governmental, academic, industrial, and general interest sectors, use a transparent consensus process that’s designed to balance the needs and interests of all, including end users. Membership on technical committees is open to any interested party, but voting membership is controlled so no company or class of member (such as producers or consumers) can exercise undue influence over the provisions and wording of a standard.

Each technical committee has jurisdiction over a broad subject, and is divided into subcommittees that focus on more specialized fields. In the concrete arena, the most relevant committees are C01 on Cement (with 19 subcommittees covering topics such as special cements, air entrainment, fineness, and time of set) and C09 on Concrete and Concrete Aggregates (with 29 technical subcommittees such as chemical admixtures, supplementary cementitious materials, and ready-mixed concrete). Between them, C01 and C09 are currently responsible for 255 standards. To keep standards current and relevant, ASTM requires that each standard be reviewed and reapproved periodically, even if no changes are made.

Types of standards

A pressure meter is used in ASTM C-231 Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method.
Portland Cement Association A pressure meter is used in ASTM C-231 Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method.

ASTM standards comprise specifications, test methods, guides, and practices.

Standard Specifications typically cover a product or material and spell out its required or permissible components and properties. Some examples include C-94 Standard Specification for Ready Mixed Concrete and C-494 Standard Specification for Chemical Admixtures for Concrete.

Standard Test Methods describe in detail the equipment and procedures used to determine and report on a product’s properties or condition. The use of standard test methods makes it possible to compare results of the same test performed on different products in different laboratory facilities. Some examples are C-33 Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens and C-143 Standard Test Method of Slump for Hydraulic Cement Concrete.

The other types of standards are much less common. Standard Practices describe procedures required to accomplish certain goals other than specific test methods, while Standard Guides offer recommendations that may be less precisely detailed or more broadly applied. Examples include C-172 Standard Practice for Sampling Freshly Mixed Concrete and C-305 Standard Guide for Petrographic Examination of Aggregates for Concrete.

Often a standard will reference other documents published by ASTM or another body such as ACI or AASHTO. For instance, a Specification may require a product to exhibit certain properties, and will reference the Test Methods that must be used to measure them.

Standard development process

Standards are developed when someone determines that they’re needed. In the construction industry, the impetus often is the introduction of a new product or practice. Designers and owners can be reluctant to use a new material or method if they don’t know much about it and can’t be sure it meets acceptable performance standards. When a new product or practice comes to the attention of the appropriate ASTM Committee, a task group of knowledgeable members will be formed to investigate it and perhaps draft a standard specification. After the draft is reviewed and revised by task group members, it gets passed along for further comments and balloting at the subcommittee, main committee, and society levels. At each level, all negative votes and comments must be considered and a consensus reached on acceptable wording. It only becomes a published standard after it is accepted by a vote of the full society. This open and transparent process gives interested ASTM members several opportunities to influence the provisions and wording of a proposed standard, and helps to ensure its clarity and consistency with existing standards.

What’s in it for me?

This process may or may not sound interesting to you, and active involvement in ASTM standards development may or may not be worth the time and costs involved in attending committee meetings twice a year. But there are inexpensive ways to keep track of changes in standards related to cement and concrete, and some good reasons you might want to do so.

The slump test ASTM C-143 is the one most commonly used to measure the consistency of fresh concrete.
Portland Cement Association The slump test ASTM C-143 is the one most commonly used to measure the consistency of fresh concrete.

Anthony Fiorato is the current chairman of ASTM Committee C09 and a former chair of ASTM’s Board of Directors. He is executive director of the Slag Cement Association, Glenview, Ill., and formerly was president of CTLGroup, Skokie, Ill., a leading consulting firm and testing laboratory for concrete and other construction materials. “Most contractors don’t think a lot about test methods, but they sometimes live and die by test results. Even though the contractor may not ultimately be responsible for low results on strength tests, for example, he’ll be affected if a job is delayed significantly because of it,” says Fiorato. “Low strength results can sometimes be due to poor testing. That can happen when the test methods are unclear, and that is an issue for the standards body to address.”

A contractor can run into problems by accepting a project specification for testing that won’t reveal what the designer wants it to. Contractors can’t always assume the specified testing regimen is correct, so they need to know: (1) What the specified test method is intended to do; (2) What the standard wants them to do to provide access for sampling; and (3) How they’re supposed to handle and protect the samples to be tested.

“The same holds true for material specifications. It behooves contractors to understand that materials they buy are subject to ASTM standards and make sure they’re buying the right ones,” says Fiorato.

In the case of disputes over concrete quality or performance, Fiorato suggests all parties meet and agree on how core tests will be done. “It’s important to review how core samples will be obtained and conditioned for testing. Samples that are handled differently can produce different results.”

Of course, a contractor doesn’t need to take part in standards development in order to become familiar with relevant standards. However, for annual dues of $75, ASTM members get to select one volume of standards, receive a subscription to the bimonthly magazine Standardization News, and are notified of all the activities of the Committees they decide to join. This gives them a heads-up when new standards are adopted and existing standards are revised.

Room for collaboration

There are areas of standards development that industry leaders think could benefit from the input of concrete contractors. One such area is test methods used to evaluate the acceptability of fresh concrete upon delivery.

Knowing how standards are developed and applied can benefit your business.
Portland Cement Association Knowing how standards are developed and applied can benefit your business.

Colin Lobo, senior vice president of engineering for National Ready Mixed Concrete Association, Silver Spring, Md., says contractors, as the primary purchasers of ready-mixed concrete, have a role to play in standards development. “It could be helpful for contractors to get involved in updates to C-94 Standard Specification for Ready Mixed Concrete. They also have a natural interest in testing related to slump, workability, resistance to segregation, setting time, and bleeding characteristics.”

Drawing on their field experience, contractors might suggest ways to make test methods more practical, convenient, and reliable in predicting when concrete is ready for finishing.

Ward Malisch, technical director of the American Society of Concrete Contractors, St. Louis, acknowledges contractors active in his and other industry organizations might give ASTM participation a lower priority. However, he would like to see contractors help change a provision of the C-94 ready-mix spec that places a 90-minute limit from water addition to full discharge, which he says leads to some unnecessary rejections of material.

Malisch points to ASTM committees beyond C01 and C09 he thinks could use their input. In both cases, standards that involve concrete used in combination with other materials are being developed, sometimes without a clear understanding of potential conflicts.

“The committee on stucco [Committee C11.03 on Specifications for the Application of Gypsum and Other Products in Assemblies] publishes a standard [C926-06 Standard Specification for Application of Portland Cement-Based Plaster] that sets up unrealistic and impractical tolerances for concrete backups. ASTM Committee F06 on Resilient Flooring writes standards dealing with concrete substrates [F710 Standard Practice for Preparing Concrete Floors to Receive Resilient Flooring is one example], and these also should get input from concrete contractors as well as other members of C09,” Malisch says.

Changes to watch for

Contractors who want to stay ahead of the curve should look for new standards in 2011 relating to self-consolidating concrete and pervious concrete. Whether or not you opt to become involved in ASTM, you can use newly developed standards as a way to introduce engineers and owners to new products and techniques. The standards process helps promote market acceptance of innovations in the construction industry and beyond.

Kenneth A. Hooker is a freelance writer based in Oak Park, Ill.