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.

"building code requirements for structural concrete (aci 318-11) and commentary"

Title: Sectional Analysis of Reinforced Concrete Members Degree: Doctor of Philosophy

Sectional analysis of reinforced concrete members

Cracked reinforced concrete in compression has been observed to exhibit lower strength and stiffness than uniaxially compressed concrete. The so‐called compression softening effect responsible is thought to be related to the degree of transverse cracking and straining present. It significantly influences the strength, ductility and load‐deformation response of a concrete element. A number of experimental investigations have been undertaken to determine the degree of softening that occurs, and the factors that influence it. At the same time, a number of diverse analytical models have been proposed by various researchers aimed at modeling this behavior. In this paper, a review is made of the experimental data available, of the various models proposed, and of the accuracy of the models in correlating to the test data. Based on new data, previously derived analytical models are updated. Parametric studies are made to investigate factors thought to influence the softening effect. As well, nonlinear finite elem...

Compression response of cracked reinforced concrete

The authors present a simple, unified method for the shear design of both prestressed concrete members and nonprestressed concrete members. The method can treat members subjected to axial tension or axial compression and treats members with and without web reinforcement. The derivation of the method is summarized and the predictions of the method are compared with those of the current American Concrete Institute (ACI) Code.

A general shear design method

Structural performance of ultra-high-performance concrete beams with different steel fibers

This paper presents the evaluation of minimum shear reinforcement requirements in normal, medium, and high-strength reinforced concrete beams. Twelve shear tests were conducted on full-scale beam specimens having concrete compressive strengths of 36, 67, and 87 MPa. Different amounts of minimum shear reinforcement were investigated including the traditional amounts required by older codes and the amounts required by the 1989 ACI Code (revised 1992) and the 1994 CSA Standard. The performance of the different amounts of shear reinforcement are discussed in terms of shear capacity, ductility, and crack control at service load levels. An assessment of the 1989 ACI and 1994 CSA provisions for minimum shear reinforcement is also presented.

Minimum Shear Reinforcement in Normal, Medium,and High-Strength Concrete Beams

Twenty-two precast, pretensioned concrete beam specimens were fabricated and tested to determine the influence of concrete strength on the transfer length and development length of pretensioning strand. The main variables were the concrete compressive strength, varying from 4500 to 12,900 psi (31 to 89 MPa), and the strand diameter, which included 3/8, 1/2 and 0.62 in. (9.5, 12.7 and 15.7 mm) diameters. Expressions are given for the influence of concrete strength on the transfer length and development length of pretensioning strand.

Influence of high strength concrete on transfer and development length of pretensioning strand

The response of slab structures after initial failure is investigated in order to determine a means of preventing progressive collapse. Analytical models for predicting the post‐failure response of slabs are presented and the predictions are compared with experimental results. These analytical models along with an experimental investigation enabled the development of simple design and detailing guidelines for bottom slab reinforcement which is capable of hanging the slab from the columns after initial failures due to punching shear and flexure.

Preventing Progressive Collapse of Slab Structures

Ductile coupled flexural walls are the primary seismic load resisting systems of many structures. The coupling beams of these structures must exhibit excellent ductility and energy‐absorption ability. To achieve better ductility and energy absorption than previously possible, the use of steel link beams with their ends embedded in the reinforced concrete walls is proposed. Preliminary experimental results are reported for two full‐scale reversed cyclic‐loading tests of portions of ductile flexural walls coupled with steel link beams. The excellent performance, together with the ease of construction, demonstrate the feasibility of this alternative form of construction. To ensure ductile response, design and detailing guidelines for both the clear span and embedded portions of the link beams and the reinforced concrete embedment region are presented. An assessment, based on comparisons with other structural systems, of this new type of construction is presented.

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Seismic response of steel beams coupling concrete walls

This paper will discuss how a series of nine full-scale reinforced concrete (RC) and steel fiber-reinforced concrete (SFRC) beams were tested to study the effects of steel fibers on shear capacity, failure mechanism, and crack control. Six of the specimens were constructed without shear reinforcement. In addition, three specimens were detailed in accordance with the minimum shear reinforcement requirements of CSA A23.3-04 to examine the influence of fibers on ductility. The results demonstrate that the addition of fibers leads to improved shear resistance in shear-deficient beams. The addition of fibers in beams that contain minimum shear reinforcement results in improved ductility and crack control. A procedure for predicting the shear resistance of SFRC beams is also presented in this paper.

William D. Cook

Papers

Minimum Shear Reinforcement in Normal, Medium,and High-Strength Concrete Beams

Influence of high strength concrete on transfer and development length of pretensioning strand

Preventing Progressive Collapse of Slab Structures

Seismic response of steel beams coupling concrete walls

Response of Steel Fiber-Reinforced Concrete Beams with and without Stirrups