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This code by American Concrete Institute (ACI) provides minimum requirements for design and construction of structural concrete elements of any structure erected under requirements of the legally adopted general building code of which this code forms a part. In areas without a legally adopted building code, this code defines minimum acceptable standards of design and construction practice. For structural concrete, fc′ shall not be less than 2500 psi. No maximum value of f c′ shall apply unless restricted by a specific code provision.

Contents

Introduction
Chapter 1—General Requirements
Chapter 2—Notation And Definitions
Chapter 3—Materials
Chapter 4—Durability Requirements
Chapter 5—Concrete Quality, Mixing, And Placing
Chapter 6—Formwork, Embedded Pipes, And Construction Joints
Chapter 7—Details Of Reinforcement
Chapter 8—Analysis And Design—General Considerations
Chapter 9—Strength And Serviceability Requirements
Chapter 10—Flexure And Axial Loads
Chapter 11—Shear And Torsion
Chapter 12—Development And Splices Of Reinforcement
Chapter 13—Two-Way Slab Systems
Chapter 14—Walls
Chapter 15—Footings
Chapter 16—Precast Concrete
Chapter 17—Composite Concrete Flexural Members
Chapter 18—Prestressed Concrete
Chapter 19—Shells And Folded Plate Members
Chapter 20—Strength Evaluation Of Existing Structures
Chapter 21—Special Provisions For Seismic Design
Chapter 22—Structural Plain Concrete
Appendix A—Strut-And-Tie Models
Appendix B—Alternative Provisions For Reinforced And Prestressed
Appendix C—Alternative Load And Strength Reduction Factors
Appendix D—Anchoring To Concrete
Appendix E—Steel Reinforcement Information
Commentary References
Index

Download: ACI Building Code 318-05 (Building Code Requirements for  Structural Concrete)

The new AISC Search Utility for Structural Steel shapes allows users to search shape properties for beams appearing in numerous past AISC publications from 1873 – 2001.The information presented in this publication has been prepared in accordance with recognized engineering principles and is for general information only. While it is believed to be accurate, this information should not be used or relied upon for any specific application without competent professional examination and verification of its accuracy, suitablility, and applicability by a licensed professional engineer, designer, or architect. The publication of the material contained herein is not intended as a representation or warranty on the part of the American Institute of Steel Construction or of any other person named herein, that this information is suitable for any general or particular use or of freedom from infringement of any patent or patents. Anyone making use of this information assumes all liability arising from such use.

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A building code is a set of rules that specify the minimum acceptable level of safety for constructed objects such as buildings. The International Building Code (IBC) is a model building code developed by the International Code Council (ICC). A model building code has no legal status until it is adopted or adapted by government regulation. The IBC provides minimum standards to ensure the public safety, health and welfare insofar as they are affected by building construction and to secure safety to life and property from all hazards incident to the occupancy of buildings, structures or premises.
Before the creation of the International Building Code there were several different building codes used, depending on where one decided to construct a building. The IBC was developed to consolidate existing building codes into one uniform code that could be used nationally and internationally to construct buildings. The purpose of the IBC is to protect public health, safety and general welfare as they relate to the construction of buildings. Therefore, it is used to regulate building construction through use of standards and is a reference for architects and engineers to use when designing buildings or building systems.

History:
The first building codes can be traced back to early 1800 BC. The Babylonian emperor Hammurabi enforced what was known as the Code of Hammurabi. This code was very strict and stated that, “If a builder build a house for someone, and does not construct it properly, and the house which he built fall in and kill its owner, then that builder shall be put to death.” Building codes have evolved over time to protect the safety of building occupants without the threat of death.
Building codes were first seen in the United States in the early 1700’s AD. George Washington and Thomas Jefferson encouraged the development of building regulations to provide minimum standards to ensure health and safety of our citizens. In the early 1900’s insurance companies lobbied for further development of building codes to reduce properly loss payouts caused by inadequate construction standards and improperly built structures. During this time period, local code enforcement officials developed most of the building codes with the assistance of the building industry.
In 1915, the Building Officials and Code Administration (BOCA) was established. This organization developed what is now known as the BOCA National Building Code (BOCA/NBC), which is/was mainly used in the Northeastern United States.

In 1927, the International Conference of Building Officials (ICBO) was established. This organization developed what is now known as the Uniform Building Code (UBC), which is/was mainly used in the Midwest and Western United States.
In 1940, the Southern Building Code Congress International (SBCCI) was founded. This organization developed what is now known as the Standard Building Code (SBC), which is/was mainly used in the Southern United States.
Over the years each of these codes (BOCA/NBC, UBC, & SBC) were revised and updated. Many of the codes were duplications of one another or very similar in nature. In order to avoid duplication and to consolidate the development process BOCA, ICBO, and SBCCI formed the International Code Council (ICC). The purpose of the ICC was to develop codes without regional limitations. In 1994 they began to develop what would become the International Building Code (IBC).
In 1997, the first edition of the IBC was published. There were still many flaws and it was not widely accepted. In 2000, the first comprehensive and coordinated set of the IBC was published. All three organizations (BOCA, ICBO, & SBCCI) agreed to adopt the IBC and cease development of their respective individual codes. The IBC supercedes the BOCA/NBC, UBC, & SBC codes and states & local governments began to adopt the new consolidated code.

Structure:
The International Building Code is arranged in a systematic manner for easy reference. It incorporates all aspects of building construction. It is made up of thirty-five (35) chapters and several appendices. The chapters in the IBC are as follows:

1) Administration 19) Concrete
2) Definitions 20) Aluminum
3) Use and Occupancy Classification 21) Masonry
4) Special Detailed Requirements Based on Use and Occupancy 22) Steel
5) General Building Heights and Areas 23) Wood
6) Types of Construction 24) Glass and Glazing
7) Fire-Resistant-Rated Construction 25) Gypsum Board and Plaster
8) Interior Finishes 26) Plastic
9) Fire Protection Systems 27) Electrical
10) Means of Egress 28) Mechanical Systems
11) Accessibility 29) Plumbing Systems
12) Interior Environment 30) Elevators and Conveying Systems
13) Energy Efficiency 31) Special Construction
14) Exterior Walls 32) Encroachments into the Public Right-of-
15) Roof Assemblies and Rooftop Structures Way
16) Structural Design 33) Safeguards During Construction
17) Structural Tests and Special Inspections 34) Existing Structures
18) Soils and Foundations 35) Referenced Codes
19) Concrete

20) Aluminum
21) Masonry

22) Steel

23) Wood

24) Glass and Glazing

25) Gypsum Board and Plaster

26) Plastic

27) Electrical

28) Mechanical Systems

29) Plumbing Systems

30) Elevators and Conveying Systems

31) Special Construction

32) Encroachments into the Public Right-of-Way

33) Safeguards During Construction

34) Existing Structures

35) Referenced Codes

Each chapter is broken down into sections and each section into sub-sections. Each section describes performance criteria to be met or references other sections of the IBC or other standards such as ANSI, ASTM, etc. The following is an excerpt from Chapter 7 of IBC 2000.

Development:
There are five subcommittees of the International Code Council (ICC) that developed and update the International Building Code (IBC). The Steering and Performance committees of the ICC oversee each of these subcommittees. The committees consisted of code officials (BOCA, ICBO, SBCCI), design professionals, trade professionals, builders and contractors, manufacturers and suppliers, and government agencies.
The General Subcommittee is responsible for development and updating of chapters 1,2,5,6,12,13 and 26-34. The Structural Subcommittee is responsible for development and updating of chapters 16-25. The Fire Safety Subcommittee is responsible for development and updating of chapters 7-9,14, and 15. The Means of Egress Subcommittee is responsible for development and updating of chapters 10 and 11. The Occupancy Subcommittee is responsible for development and updating of chapters 3 and 4.
The development of the IBC typically runs in eighteen-month (18) cycles. The first step is accepting applications for code committees and code change proposals. The next step is to publish the proposed changes. The third step is to hold public hearings on the proposed changes. Next the minutes from the hearing are published. The following step is to collect public comments. The fifth step is to publish the public comments. Next the final public hearing is held. After the final public hearing the annual ICC meeting is held. Finally the revised or new code is published. Below is an example code development schedule from the ICC.

New editions of the IBC are published every three (3) years. Amendments to the 2000 edition were issued in 2003 and 2006. In between edition revisions, intervening supplements are published. The last supplement was issued in 2004. The amendments are issued to incorporate approved changes, lessons learned and new technology. All the changes in the new editions are indicated by markings in the margins.

Use in Government Regulation:
The Constitution of the United States of America grants states jurisdiction over regulation of building construction. The International Building Code (IBC) is designed to be adopted by reference by ordinance. Forty-seven (47) states including Washington, DC, the U.S Department of Defense, and the National Park Service have adopted the IBC or parts of it into government regulation. Local building code officials mainly regulate the enforcement of the IBC.Several states including Arkansas, California, Georgia, and Florida have amended versions of the IBC and incorporated the amendments into their building codes. California has yet to adopt the IBC due to disputes between the ICC and National Fire Protection Agency (NFPA). The NFPA has developed its own code NFPA 5000 to offer the industry an ANSI-accredited, consensus-based alternative to the IBC. It is expected that within the next five years all states will incorporate some form of the IBC.

Conclusion:
The development of the International Building Code has been an advancement for the building and construction industry. It provides minimum standards to insure the public safety, health and welfare insofar as they are affected by building construction and to secure safety to life and property from all hazards incident to the occupancy of buildings, structures or premises. The IBC is a single source document that is adopted across the United States. This allows contractors to learn one code instead of the several that use to exist depending on the region where the work was performed. Without the IBC or building codes, people would have to think twice before entering structures or their homes.

References:

Reinforced concrete is made of two materials, concrete and reinforcing steel.Concrete is made of five parts:

The compressive strength (fc’) of concrete is the 28-day strength. This could be from 2,500 psi to 20,000 psi. Most concrete used is between 3,000 psi to 6,000 psi. Concrete is very good in compression but its tensile strength is only about 8 to 15% of the compressive strength. This is the reason why we need reinforcing steel.When we load a beam, the bottom is in tension. Reinforcement could be fiber-reinforcement or reinforcing steel. In this course, we will only look at reinforcing steel. Reinforcing steel comes in the following sizes, areas, weights and diameters:

Reinforcement steel comes in the followingdesignations,types, grades, strengths and available sizes.It appears from the above table, A615, grade 60 and A706, grade 60 cover all sizes.

 We use figure c, rectangular. The ACI code says for concretes with fc’>4,000 psi, β can be determined with the following formula:

The ACI code says design value must be greater than or equal to the required value.

Note: When the code specifies a minimum and they give two or more formulas, we use the formula that yields the maximum. For example, if one formula gives 16 sq inch and the other formula gives 18 sq inch, then the minimum would be 18 sq inch. Also, bw is the width of the beam.
ACI (10.2.3) states that the maximum usable strain at extreme concrete compression fiber shall be assumed equal to 0.003. In other words, εc=0.003.

 It is desirable, under ordinary conditions, to design beams with a steel ration (ρ) between ρ min and ρ max.

Load factors are numbers, used to increase the estimated loads applied on a structure. The loads are increased to account for the uncertainties involved in estimating the magnitude of the loads. How good can you estimate the loads on the floor where you are right now? Sections 9.2 gives the required strength based on load factors and combinations of loads:

D=dead loads, F=weight and pressure of fluids, T=temperature, creep, shrinkage and differential settlement, L=live loads, H=weight and pressure of soil, water in soil or other materials, Lr=roof live loads, S=snow loads, R=rain loads, W=wind loads and E=earthquake loads.

Section 9 gives the following table for minimum depth of beams:

In Section 7.7.1 of the code, it specifies the amount of cover for the reinforcement. Cover is the distance from the edge of the reinforcing bar to the face of the concrete beam. For beams with primary reinforcement, ties, stirrups and spirals, it is 1 ½ inches when the concrete is not exposed to weather or in contact with the ground.

In section 7.6 of the code, it specifies the minimum clear spacing between parallel bars in a layer to be db or 1”, whichever is larger. Remember, when the code specifies the minimum and gives you two or more items, you use the larger of the values. As a rule of thumb, beams 20-25 feet long have a ratio of d to b of 1.5 to 2. For longer beams the ratio of depth to width may be as high as 3-4. Beam dimensions are selected in whole inches. The width is usually a multiple of 2 or 3. Beams should probably not be less than 12” wide to get the steel and your hands in the form. For the usual situation, use bars of size # 11 and smaller if possible. Rarely will you use # 14 or # 18 bars.