The code portion of this document covers the design and construction of structural concrete used in buildings and where applicable in nonbuilding structures. The code is written in a format that allows such reference without change to its language. Therefore, background details or suggestions for carrying out the requirements or intent of the code portion cannot be included. The commentary is provided for this purpose. Some of the considerations of the committee in developing the code portion are discussed within the commentary, with emphasis given to the explanation of new or revised provisions. Much of the research data referenced in preparing the code is cited for the user desiring to study individual questions in greater detail. Other documents that provide suggestions for carrying out the requirements of the code are also cited.