Post-tensioned Concrete Floors

Abstract

This book deals with the design of concrete building structures incorporating post-tensioned floors. Post-tensioning is the most versatile form of prestressing, a technique which enables engineers to make the most effective use of the material properties of concrete, and so to design structural elements which are strong, slender and efficient. Design in post-tensioned concrete is not difficult and, if done properly, can contribute significantly to the economy and the aesthetic qualities of a building. As a result, post-tensioned floors have found widespread use in office buildings and car park structures, and are also frequently employed in warehouses and public buildings. However, in spite of this, most prestressed concrete texts devote comparatively little attention to floors, concentrating instead on beam elements. This book therefore aims to answer the need for a comprehensive treatment of post-tensioned floor design. The first four chapters of the book give a detailed, non-mathematical account of the principles of prestressing, the materials and equipment used, and the planning of buildings incorporating post-tensioned floors. The following chapters outline the detailed design process, including numerous worked examples, and the book concludes with chapters describing site procedures for construction, demolition and alteration. While the reader is assumed to have a grasp of the basics of reinforced concrete design, no prior knowledge of prestressing is required. The book is thus suitable for use by architects, contract managers and quantity surveyors who may wish to gain an understanding of the principles without going into the mathematical aspects of the design process, as well as structural engineers requiring detailed design guidance. It is also intended for use as an educational text by students following civil engineering, architecture and building courses. The title of the book reflects the fact that its emphasis is on the behaviour and design of the floors themselves. Thus, while the effect of post-tensioned floors on other structural elements such as columns and walls is considered, detailed guidance on the design of these elements is not given; such information can be obtained from any one of the many excellent reinforced concrete design texts already available. Neither does this book deal with the prestressing of building elements other than floors, such as foundations, moment-resisting columns or vertical hangers. These elements are comparatively rare, or are not usually prestressed. If guidance on design of such elements is required, reference should be made to specialist literature. In any book on post-tensioning comparisons with reinforced concrete are