Concrete publications

Three new publications are available from The American Concrete Institute. The first publication, titled 347.2R-05—Guide for Shoring/Reshoring of Concrete Multistory Buildings, presents information and design criteria for shoring/reshoring operations during the construction of reinforced and posttensioned multistory buildings. It provides methods for developing safe construction schedules and provides design examples. Guide 209.1R-05—Report on Factors Affecting Shrinkage and Creep of Hardened Concrete describes the effects of numerous variables on shrinkage and creep of hardened concrete, including mixture proportions, environment, design, and construction. The third publication—309R-05—Guide for Consolidation of Concrete—includes information on the mechanism of consolidation and gives recommendations on equipment, characteristics, and procedures for various classes of construction.

The American Concrete Institute

Concrete admixtures

Degussa Admixtures, Inc., is using a system of Master Builders-branded technologies to develop pervious concrete mixtures that are contractor friendly and improve final performance. Pervious concrete, also referred to as low-fines or nofines concrete, is a mix of portland cement, coarse aggregate, water, and admixtures. Because of the lack of fine aggregate, the pervious concrete pore structure contains many voids, allowing water to pass through. While pervious concrete has been accepted and used in specific regions of the United States, recent changes in federally mandated stormwater management regulations have fueled new interest. Pervious concrete gives ready-mixed concrete producers another tool and an environmentally friendly alternative to offer builders in their marketplace.

Degussa Admixtures, Inc.

Concrete testing equipment

Forney Inc., introduces the first products available for testing self-consolidating concrete (SCC). This lower-viscosity concrete requires unique instruments to determine its slump flow, passing ability, and static segregation.

The Forney J-Ring Test Set (LAG-3770) features a heavy-duty steel J-Ring and a large, rigid plastic base plate. Testing spread and restricted flow around rebar and other reinforcing structures, the set can be used in the laboratory to compare the passing ability of different mixtures, or in the field for quality control testing. SCC must also be of a high fluidity yet resist segregation. The Forney Column Segregation Test Set (LAG- 3771) determines the degree of potential segregation of coarse aggregate in SCC mixtures.

Forney Inc.

Specifier’s guide

The Specifier’s Guide to Durable Concrete, a new handbook from the Portland Cement Association (PCA), provides instruction and basic references for those who specify and work with concrete.

Industry information is presented in a logical, easy-to-follow format. In addition to providing users with what they need to select materials and mix design parameters to achieve durable concrete regardless of the environment, the guide also alerts them when to seek expert help. The Specifer’s Guide—intended as a companion to PCA’s Design and Control of Concrete Mixtures—covers the basic concepts of concrete technology as it relates to durability. It explains the various mechanisms of concrete deterioration and how to increase durability under these conditions.

Portland Cement Association

Design manual

The Post-Tensioning Institute, announces the availability of the 3rd edition of its design manual, Design of Post- Tensioned Slabs-on-Ground. This edition focuses on geotechnical design parameters, which include extensive editorial revisions and clarification. All procedures are provided to guide the designer to the applicable design system and its limitations.

This new technical guide was produced for qualified geotechnical and structural engineers for the design of two types of post-tensioned ground-supported foundations—ribbed foundations and uniform thickness foundations. Major areas of interest include slabs on stable soils, geotechnical investigation, soil-structure interaction, and structural design procedure for shallow post-tensioned foundations.

The Post-Tensioning Institute