Reinforced concrete in ACI Code

Fri 10 Feb, 21:58

In the United States and throughout the world, the design and construction of building structures is regulated by building codes. The main purpose of a building code is to protect public health, safety, and welfare. Building code provisions are founded on principles that do not unnecessarily increase construction costs; do not restrict the use of new materials, products, or methods of construction; and do not give preferential treatment to particular types or classes of materials, products, or methods of construction.

Manycities, counties, and states in the United States and some international jurisdictions have adopted the International Building Code (IBC) for the design and construction of building structures. The provisions of the 2009 edition of the IBC are covered in this book.1 Chapter 16 of the IBC prescribes minimum nominal loads that must be used in the design of any structure. Chapter 3 contains a summary of these loads as they pertain to the design of reinforced concrete buildings.

Section 1901.2 of the IBC requires that structural concrete be designed and constructed in accordance with the provisions of Chap. 19 of the IBC and the 2008 edition of Building Code Requirements for Structural Concrete (ACI 318–08) and Commentary.2 ACI 318–08 is one of a number of codes and standards that is referenced by the IBC. These documents, which can be found in Chap. 35 of the 2009 IBC, are considered part of the requirements of the IBC to the prescribed extent of each reference (see Section 101.4 of the 2009 IBC). Amendments to ACI 318–08 are given in IBC Section 1908.

Even though it is an American Concrete Institute (ACI) standard, ACI 318 is commonly referred to as the “ACI Code” or the “Code.” The ACI Code provides minimum requirements for the design and construction of structural concrete members (see Section 1.1 of that document). The term “structural concrete” refers to all plain and reinforced concrete members used for structural purposes. Section 1.1 also identifies the types of concrete members that are not addressed in the Code and includes general provisions for earthquake resistance.

Throughout this book, section numbers from the 2009 IBC are referenced as illustrated by the following: Section 1901.2 is denoted as IBC 1901.2. Similarly, Section 10.2 of the ACI Code is referenced as ACI 10.2 and Section R10.2 of the Commentary is referenced as ACI R10.2.
It is important to acquire the building code of the local jurisdiction at the onset of any project. Local building authorities may have amended the IBC or other adopted codes, and it is the  responsibility of the registered design professional to be aware of such amendments before designing the building.