The American Concrete Institute’s new Concrete Knowledge Center

At the turn of the 20th century, concrete was a relatively new building material, and there were many questions of how to best use it. The American Concrete Institute (ACI) was formed as a platform where knowledgeable people could meet, discuss subjects of interest, and publish consensus, unbiased, reliable information on the many aspects of concrete and the concrete infrastructure.

Concrete continues to be an interesting and challenging building material. As we move into the 21st century, there is a broad diversity of possible constituent materials, geometries, environments, and purposes involved in concrete construction; so access to an ever-widening range of concrete-related knowledge is needed to make informed decisions.

Recently, ACI created the Concrete Knowledge Center (CKC), a distinct site within the ACI website, leveraging both ACI’s printed information and the expertise of ACI’s many knowledgeable members. While only a few months old, the CKC is developing into a powerful tool to assist the public and ACI members in finding information important to their objectives.

The CKC is an open website containing information on materials, design, construction, and repair of concrete. Several in-depth features are provided exclusively to ACI members. The majority of information has been vetted by the experts on ACI committees. When information from sources outside ACI is relevant, helpful, and available, it is posted (with the source identified) or a hyper-link is provided.

Available to the public

Technical questions—ACI receives many questions from individuals interested in obtaining reliable information on concrete materials, construction, and repair as that information relates to their projects. The CKC provides a convenient web-area where the public can find answers to dozens of frequently asked questions, such as the following:

* Is there a maximum acceptable free-fall distance for concrete placement?
* What is the relationship between F-numbers and straightedge flatness tolerances for floors?
* What physical properties of cement-based repair materials are important to minimize cracking in repairs?
* How much concrete cover is needed for a concrete slab to meet a four-hour fire rating?

Educational bulletins—Bulletins fall into two categories: introduction to concrete and repair procedures.

Within the introduction to concrete, the materials of concrete and reinforced concrete are presented in four educational bulletins: aggregates, reinforcement, cementitious materials, and chemical admixtures. The bulletins provide an overview of these topics, with references to other documents that provide more detailed information.
Additionally, nine bulletins provide an overview of various concrete repair techniques. Step-by-step procedures are provided, including information on the purpose of repair, when it should be used, needed surface preparation, material, and equipment selection.

Repair-related presentations by experts—There is a quick link to "http://www.fixconcrete.org," a site (free registration required) that contains hundreds of repair-related presentations recorded at ACI and International Concrete Repair Institute (ICRI) convention sessions over the past several years.

Available to members

From the beginning of the CKC concept, ACI wanted to assist younger users of ACI 318-05 with information to better understand the code. There are currently three sections that provide this assistance: 318 Q&A; 318R-05 References; and 318 Design Case Studies.

318 Q&A—Similar to Technical Questions, this section answers common 318-related questions. Currently, there are answers to 24 questions related to clarification or interpretation of ACI 318. In addition, questions and answers will be posted as they are developed and vetted.

318R-05 References—The commentary to ACI 318-05 contains more than 400 references to research papers, standards, text books, and manuals. The committee cites these references to help the user understand the tests or analyses that were seen as important to the code committee when they were creating the code provision. By reviewing this information, the user may be better able to determine how to apply the code provision to an individual condition. The individually authored papers to 292 references are now available for full view. Copyright permissions from 27 publishers have been obtained so that access is as easy as a click of the button.

318 Design Case Studies—When faced with the responsibility of designing a building, one question younger engineers have to answer is "Did I address all the relevant code provisions?" As a main goal of each case study, ACI is providing a tool to help answer this question. While most buildings have unique challenges, there are also many similarities. Having a worked-out, real-life example should be a good starting point for understanding the relationship between the code and the building’s design.

Each case study is a detailed summary of an actual building design, with the information supplied by the responsible design engineer. Design information is presented in an indexed manner, going from general to more specific. The case study outline was made to be similar to how most engineers proceed on a project; see images above.

Project information—The engineer gathers all relevant data from architects, geotechnical engineers, and codes, and in turn, develops material and field criteria for the project.

Structural analysis and model assumptions—The engineer creates a model of the building for analysis. Analysis is typically completed by software, after which hand calculation, "reality checks" are made.

Member design and detailing—Once the moments and forces are calculated, the individual members (slabs, beams, columns, walls, and foundations) can be designed and detailed.

Miscellaneous design and detailing—After designing the main members of a building, the miscellaneous members, such as stairs, are designed. While these members are called miscellaneous, they are sometimes more conceptually difficult than the main members.

Drawings—Finally, the project drawings are created, reflecting the information generated through the design process.

Each page is in a two-column format. The left column shows the design step, and the right reproduces code provisions relevant to that step, or provides a reference for users who want more in-depth information. Because the information is web-based, there are many links at all stages to increase the ease of finding information.

Troubleshooting—Also included in the members area is the Troubleshooting section. Each troubleshooting page provides in-depth information on the topic, including definition, picture, full-text articles, and additional references.

Summary

ACI plans to continue adding more technical information to this site periodically. We hope it will be of practical use to engineers and others with an interest in concrete!

Daniel Falconer is managing director of engineering at the American Concrete Institute. He can be reached at Daniel.Falconer@concrete.org.