There is more to design than calculating the forces in the structural members and proportioning the sections. Good structural analysis and design must be complemented with appropriate reinforcement detailing to insure that the structure as a whole behaves as it is modeled by the designer. On the other hand, a poorly detailed structure may suffer from unsightly cracks, excessive deflection or even collapse. Good details and bar arrangements should be practical, buildable, cost-effective, and suitable for their intended use.
Reinforcement is provided mainly to resist internal tensile forces calculated from analysis. Also, reinforcement is provided in compression zones to increase the compression capacity, enhance ductility, reduce long term deflections, or increase the flexural capacity for beams. The ACI 318 Building Code
provides provisions for reinforcement detailing to prevent excessive crack width under service conditions.
In addition, reinforcement is required to prevent excessive cracking resulting from shrinkage or temperature changes in restrained structural elements. Lateral reinforcement (stirrups, ties and hoops) are used to provide resistance to principal tensile stresses resulting from shear. Lateral reinforcement in highly stressed areas of compression zones of columns beams and joint provides confinement. This is important especially in structures located in high seismic risk zones.
It is important to provide the adequate area of reinforcement required to resist internal tensile or compression forces required to attain the design section strength. The provided area of reinforcement is not fully effective unless it is fully developed. The fundamental requirement for development of reinforcing bars is that a reinforcing bar must be embedded in concrete a sufficient distance on each side of the critical section to develop the peak tension or compression force in the bar at the section. The reinforcement may be developed by embedment length, hooks, mechanical anchorage devices, headed deformed reinforcement, or a combination of these methods.
In addition to providing the sufficient areas of reinforcement and the required development lengths, good detailing should be done considering the overall structural integrity. The overall ability of a reinforced concrete structure to withstand abnormal loads resulting from unforeseen events, which cannot be considered in design, can be enhanced substantially by providing relatively minor changes in the detailing of the reinforcement. The American Concrete Institute’s Building Code Requirements for Structural Concrete (ACI 318-08) Section 7.13 (and others) set forth provisions for structural integrity reinforcement intended to enhance continuity, improve the redundancy and ductility of structures. This is achieved by providing, as a minimum, some continuity reinforcement or tie between horizontal framing members.
ACI 318-08 Building Code Requirements for Structural Concrete and Commentary (LT311)
This most recent edition of the ACI Building Code. Includes revisions to the 2005 edition and provides minimum requirements for the design and construction of reinforced concrete structural elements. Written in such format that it may be adopted by reference in a general building code. Published by American Concrete Institute.
Seismic Detailing of Concrete Buildings (SP382)
This publication contains a comprehensive summary of the seismic detailing requirements contained in Building Code Requirements for Structural Concrete (318-05) and Commentary (318R-05), which is adopted by reference in the 2006 International Building Code. A supplemental CD is included with reinforcement details for beams, columns, two-way slabs, walls and foundations.
ACI Detailing Manual-2004
This comprehensive detailing manual is broken down into three sections: (1) a standard on details and detailing of concrete reinforcement, (2) a manual of engineering and placing drawings, and (3) a supplementary section containing supporting reference data. Published by ACI.
Placing Reinforcing Bars - 8th Edition
Upon reading this reprinted article and completing the quiz to earn CEU credits, the reader will learn how to minimize the likelihood of cracking and improve the durability of mass concrete by optimizing the mix design, as well as predicting, monitoring, and controlling concrete temperatures.
PCA Notes on ACI 318-08 Building Code Requirements for Structural Concrete with Design Applications (EB708)
The tenth edition of this classic PCA resource has been updated to reflect code changes introduced in the latest version of Building Code Requirements for Structural Concrete, ACI 318-08. These notes will help users apply code provisions related to the design and construction of concrete structures. Each chapter of the manual starts with a description of the latest code changes. Emphasis is placed on “how-to-use” the code. Numerous design examples illustrate application of the code provisions.
Simplified Design: Reinforced Concrete Buildings of Moderate Size and Height (IS84.02P)
The publication presents timesaving analysis, design, and detailing methods for reinforced concrete buildings, particularly economical for buildings with one- to seven-stories. Revised and updated to ACI 318-02, it incorporates loading calculations and seismic design provisions in accordance with IBC 2003 and ASCE 7-02.
Structural Integrity Requirements for Concrete Buildings
This bulletin is a part of a series published by the Portland Cement Association and intended to cover different aspects of concrete design. The bulletin discusses the background and introduces the ACI 318-05 Code requirements for structural integrity.
Development and Splicing of Flexural Reinforcement Based on ACI 318-08
Upon reading this reprinted article from Structural Engineer and completing the quiz to earn CEU credits, the reader should be able to understand and learn the ACI 318-08 Code provisions for development of flexural reinforcement.
Structural Integrity Requirements for Concrete Buildings
Upon reading this reprinted article from Structural Engineer and completing the quiz to earn CEU credits, the reader will learn, the reader should be able to understand the structural integrity requirements for reinforced concrete buildings in accordance with the American Concrete Institute’s Building Code Requirements for Structural Concrete (ACI 318-05). The reader will learn the detailing provisions to achieve structural integrity for cast-in-place joists, beams, two-way slabs, lift slabs, and precast concrete construction.
An Engineering Guide to: Concrete Buildings and Progressive Collapse Resistance
The response of reinforced concrete buildings to blast load is discussed. The U.S. General Services Administration (GSA) progressive collapse analysis and guidelines are introduced. The results of a PCA study on applying the GSA method of analysis to concrete moment resisting frame buildings is presented. The publication also includes a brief introduction to blast load.