ACI SP-344

The design and analysis of structural concrete elements is a topic of practical interest. While sometimes the effect of torsion is only addressed based on simple examples, practicing engineers are faced with the need to include the effects of torsion in their designs of a variety of structures and load arrangements.

This Special Publication (SP) contains papers about the design of reinforced and prestressed concrete elements for torsion. The focus of the SP is on practical design examples according to different concrete bridge and building codes. In addition to the design examples, papers dealing with the current state of the art on torsion in structural concrete, as well as recent advances in the analysis and design of concrete elements failing in torsion, are added.

The objectives of this SP are to provide practicing engineers with the tools necessary to better understand and design concrete elements for torsion. The need for this SP arose after the development of the State-of-the-Art Report on Torsion of Joint ACI-ASCE Committee 445 "Shear and Torsion" and Subcommittee 445-E "Torsion". Usually, the attention that is paid to torsion in engineering education is limited to simplified textbook examples. The examples in this SP show applications in bridges and buildings, where the torsion design is combined with the design for flexure and shear. Additionally, the examples in this SP give insight on the different outcomes when using different bridge and building codes. Finally, the papers that include theoretical considerations give practicing engineers a deeper understanding and background on torsion in structural concrete.

The views from an international group of authors are included in this SP, subsequently representing a variety of building and bridge codes the engineer may encounter in practice. In particular, authors from the United States, Canada, Ecuador, the Netherlands, Italy, Greece, and the Czech Republic contributed to the papers in this SP. Views from academia and the industry are included.

To exchange experience in the design of torsion-critical structures as well as new research insights on torsion, Joint ACI-ASCE Committee 445 and Subcommittee 445-E organized two sessions titled "Examples for the Design of Reinforced and Prestressed Concrete Members under Torsion" at the ACI Fall Convention 2020. This SP contains several technical papers from experts who presented their work at these sessions, in addition to papers submitted for publication only.

In summary, this SP addresses numerous practical examples of structural elements under torsion in bridges and buildings, as well as insights from recent research applied to practical cases of elements under torsion. The co-editors of this SP are grateful for the contributions of the authors and sincerely value the time and effort they invested in preparing the papers in this volume, as well as the contributions of the reviewers of the manuscripts.