The “Building Code Requirements for Structural Concrete” (“Code”) covers the materials, design, and construction of structural concrete used in buildings and where applicable in nonbuilding structures. The Code also covers the strength evaluation of existing concrete structures. Among the subjects covered are: contract documents; inspection; materials; durability requirements; concrete quality, mixing, and placing; formwork; embedded pipes; construction joints; reinforcement details; analysis and design; strength and serviceability; flexural and axial loads; shear and torsion; development and splices of reinforcement; slab systems; walls; footings; precast concrete; composite flexural members; prestressed concrete; shells and folded plate members; strength evaluation of existing structures; provisions for seismic design; structural plain concrete; strut-and-tie modeling in Appendix A; alternative design provisions in Appendix B; alternative load and strength reduction factors in Appendix C; and anchoring to concrete in Appendix D. The quality and testing of materials used in construction are covered by reference to the appropriate ASTM standard specifications. Welding of reinforcement is covered by reference to the appropriate American Welding Society (AWS) standard. Uses of the Code include adoption by reference in general building codes, and earlier editions have been widely used in this manner. 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.

The behavior of an eight-story, reinforced concrete apartment building that suffered severe structural damage during the 1985 Chile earthquake is investigated. A series of linear and limit analyses are described in an attempt to identify the cause of the collapse. The results indicate that global response parameters, such as base-shear strength and mean drift ratio, are insufficient to explain the observed damage. The building had been designed with strength and stiffness characteristics comparable to other buildings that survived the earthquake with light to moderate damage. Investigation of the behavior of individual members leads to the conclusion that the building collapsed after the longitudinal reinforcement fractured in a first-story wall. This form of brittleness is related to under- rather than overreinforcement. The observed failure and data from laboratory tests demonstrate that minimum amounts of longitudinal reinforcement should be established in seismic-design requirements for structural walls.