PTI DC20.9 PDF

Scope and overview

This guide provides basic knowledge about posttensioning design and construction within the scope outlined in the following and is primarily intended for design professionals but can also be used by others involved with the design and construction of post-tensioned concrete buildings.

The scope of this document is limited to different kinds of post-tensioned concrete buildings, including parking structures that are designed in accordance with ACI 318, "Building Code Requirements for Structural Concrete and Commentary" (ACI Committee 318 2008). Although some aspects may be applicable to bonded post-tensioning, this document focuses on design and construction with singlestrand unbonded post-tensioning.

Chapter 2 provides an overview of typical post-tensioned floor systems, types of available post-tensioning systems, and durability considerations. Chapters 3 and 4 address the specifics of one-way beam and slab systems and two-way slab systems. Chapter 5 provides important information regarding proper design and detailing to minimize effects of restraint-to-shortening (RTS) due to stiff vertical elements. Lateral load considerations are also mentioned. Chapter 6 includes preliminary design tables that give the reader a feel for preliminary member sizes and the magnitude of post-tensioning and nonprestressed reinforcement requirements that can be used for preliminary estimation of material quantities. Many different types of slab and beam configurations are tabulated, including one- and two-way systems. Chapter 7 provides guidance and illustrations of proper design and construction details. Detailing is an important part of a constructible and durable design and will determine proper performance of the structure for the intended use and design life. Finally, Chapter 8, which covers structural observation and field personnel certification, highlights the need for proper training and the importance of field inspection. While this document focuses more on unbonded post-tensioning, many of the same engineering concepts apply to bonded post-tensioning.