Although many practicing engineers have access to finite element software that can perform heat transfer and stress analyses, this software often doesn’t include modules for evaluating diffusion problems. This can make it difficult to analyze a concrete structure or component for the effects of moisture loss over time. The technique described in this article takes advantage of the analogy between diffusion and heat transfer equations to allow commonly available software to analyze concrete structures for stresses arising from restrained drying shrinkage.

Pervious concrete’s perceived lack of durability when subjected to cycles of freezing and thawing initiated several research projects at Iowa State University. Since late 2004, several aspects of pervious concrete have been investigated to determine mixture proportions for cold-weather regions of the U.S. The results of these studies are summarized in this article.

Delaminations in concrete floor slabs can be difficult to repair in a cost-effective and timely manner. A newly developed product that uses a two-part hybrid polyurethane with a viscosity similar to water can significantly reduce the difficulty of performing delamination repairs by easily flowing up to 10 ft (3 m) from an injection point and penetrating deep into concrete surfaces. The product also speeds up repair by setting in only 10 minutes, allowing the repair to be checked by sounding only 30 minutes after product placement.

Modern warehouses designed with very narrow aisles between tall racks require tight tolerances on floor flatness for efficient movement of lift trucks within these defined traffic lanes. Unfortunately, specifying the proper floor tolerances for the intended lift trucks and rack height is often overlooked. An explanation of F-min floor tolerances and why they are appropriate for this application are provided.

To help innovative research make the final leap from the lab to the field, the ACI Foundation and the Charles Pankow Foundation signed a 3-year agreement at the ACI Spring 2008 Convention in Los Angeles, CA. The ACI Foundation will help identify industry research needs and recommend worthy projects. The Charles Pankow Foundation will then select, fund, and manage research projects that meet its criteria. The ACI Foundation will also help disseminate the research results to reach a wide range of industry users.

Before the ACI Spring 2008 Convention, the Technical Activities Committee (TAC) selected 73 Chairs for ACI technical committees and TAC subcommittees.

The Concrete Foundations Association (CFA) has named its 2008 Basement of the Year award winners. A total of four projects in various markets across the U.S. earned honors this year.

ACI 318 is arguably one of the most influential concrete codes in the world and a primary reason for ACI’s reputation as a leading source of technical information on the use of concrete. The basic framework of the Code was established in 1963 to introduce strength design and has remained basically unchanged ever since. To ensure that the Code continues to serve as a primary resource for the construction industry, ACI Committee 318 has elected to step back and examine the document’s organization. This article presents the case for reorganizing the Code and discusses why it may be prudent to do so at this time.