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This paper summarizes the initial phases of the technical justification for proposed design provisions for AAC structures in the US. It is divided into two parts. The first part gives general background information, and presents an overall design strategy. Autoclaved aerated concrete (AAC), a lightweight cementitious material originally developed in Europe more than 70 years ago and now widely used around the world, has recently been introduced into the US construction market. AAC elements can contain conventional reinforcement in grouted cores, either alone or with factory-installed reinforcement. To facilitate the use of AAC in the US market, an integrated seismic-qualification program has been carried out, involving general seismic design provisions, specific element design provisions, and material specifications. The second part describes the design and testing of a suite of 14 AAC shear wall specimens, with aspect ratios from 0.6 to 3, under in-plane reversed cyclic loads at the University of Texas at Austin. The results of these tests have been used to develop predictive models and reliable design equations for AAC shear walls, the primary lateral force-resisting element of AAC structural systems.

Autoclaved aerated concrete (AAC) is a lightweight uniform cellular material, first developed in Sweden in 1929. Since that time, AAC building components have been widely used in Europe and other parts of the world. Until recently, however, AAC was relatively unknown to the United States precast construction market. Today, AAC is gaining rapid acceptance in the United States due primarily to increasing energy cost and environmental concerns. Although AAC is a well-recognized building material in Europe, very little research work has been done on American-produced AAC components. The goal of the testing program was to further develop the database of the material properties and structural behavior of American-made AAC by testing plain AAC elements from three different manufacturers. Manufacturers and designers will be provided with information that will help to promote AAC as a reliable engineered construction material in the U.S. Tests performed on the plain AAC consisted of compressive strength, flexural tensile strength, shear strength, and modulus of elasticity.

SP-226 Since its inception more than 80 years ago, autoclaved aerated concrete (AAC) has enjoyed a reputation for excellent thermal insulation, acoustic, and fire-resistant properties due to its low density and cellular structure. The production and use of AAC in the United States, however, did not start until the mid 1990s. To promote and encourage the use of AAC and other ultra-lightweight concrete, ACI Committee 523, Cellular Concrete, and ACI Committee 229, Controlled Low-Strength Materials, organized a technical session on "Controlled-Density/Controlled-Strength Concrete Materials at the 2003 ACI Spring Convention in Vancouver, Canada, and a session on "Aerated Concrete - An Innovative Building Solution" at the 2003 ACI Fall Convention in Boston. Thirteen papers were presented at these two technical sessions covering a wide range of practical case studies and research projects on different types of ultra-lightweight concretes, with particular focus on AAC. These papers should be of interest to the practicing engineers, educators, and researchers in that they demonstrate the effective use of AAC as well as other types of ultra-lightweight concrete materials. This special publication (SP) contains eight of the 13 papers presented at the session. Six of the papers deal with AAC and cover a wide variety of topics including material properties, structural design, seismic performance, and design examples. The other two papers address the acoustic and structural properties of foamed and/or aerated lightweight concretes cured at room temperature.

A general overview of the approach to the design of autoclaved aerated concrete (AAC) structural walls and floor/roof panels is presented. Variations in design approach from concrete and masonry, and design equations specific to AAC are discussed and provided. Design examples illustrate the proposed approach.

This paper is a summary of ACI 523.5R, which is a guide for using autoclaved aerated concrete panels. Its design provisions are non-mandatory, and are a synthesis of design recommendations from the Autoclaved Aerated Concrete Products Association, and from the results of research conducted at the University of Alabama at Birmingham (UAB), the University of Texas at Austin (UT Austin), and elsewhere. This paper discusses the design equations associated with the various typical structural uses of autoclaved aerated concrete. Those uses include flexural, axial compression, shear, bearing, bond and development of reinforcement and special seismic design provisions. The design provisions of this Guide are not intended for use with unreinforced, masonry-type AAC units. Design of those units is covered by provisions currently under development within the Masonry Standards Joint Committee.