Unbondable

Static shear, fatigue shear, and compression tests were made on an aluminum honeycomb core material. Bending and compression tests were made on sandwich panels having this core material and aluminum facings. The bonds between the honeycomb cells of some of the core material were completely removed. The modulus of rigidity and the shear strength of the unbonded material were found to be about 70% of those of the well-bonded material. The compressive strength of the unbonded material is about 50% of that of the well-bonded material, which is consistent with the assumption that the compressive strength is proportional to the critical compression stress of the cell walls.

Unbonded tendons are popular in certain types of structure for reasons of economy and speed of construction. The FIP Commission on Pre-stressing Steels and Systems accordingly appointed an ad hoc committee to investigate available knowledge and experience and to instigate research if necessary.

This multi-contributor book provides comprehensive coverage of earthquake engineering problems, an overview of traditional methods, and the scientific background on recent developments. It discusses computer methods on structural analysis and provides access to the recent design methodologies and serves as a reference for both professionals and res

The first edition of this comprehensive work quickly filled the need for an in-depth handbook on concrete construction engineering and technology. Living up to the standard set by its bestselling predecessor, this second edition of the Concrete Construction Engineering Handbook covers the entire range of issues pertaining to the construction

The development of prestressing technology has constituted one of the more important improvements in the fields of structural engineering and construction. Referring particularly to post-tensioning applications, it is generally recognized how it opens the possibility to improve economy, structural behaviour and aesthetic aspects in concrete solutions. In spite of the simplicity of its basic concepts and well-known advantages, the application extent of post-tensioning solutions cannot be considered harmonized in the different areas and structural applications. In fact, for various reasons, it appears that the potential offered by prestressing is far from being fully exploited, especially in building structures field. In many cases where post-tensioning would provide a visibly superior solution, it happens after all that a more conventional non-prestressed solution is often selected. The main objective of this fib Technical Report is therefore to show the benefits of using post-tensioning for the more common practical applications in concrete buildings. The document is mainly addressed to architects, contractors and owners. It is also drafted with the goal of motivating building designers to use post-tensioning: basic design aspects related to prestressing effects and design criteria are summarized and conceptual design aspects are emphasized. A set of practical examples is presented, showing the adopted solutions and their advantages when meeting the requirements of specific problems. The selected examples were precisely not chosen because they are outstanding structures. As a matter of fact, post-tensioning principles and technology can be used in any structure, independently of its importance, covering a wide range of building structural applications, improving the structure quality and promoting concrete as a structural material. The advantages of using post-tensioning, concerning structural behaviour, economy, detailing and constructive aspects, are illustrated by the presentation of several existing structures, most of them designed by Working Party members. General design calculations are not presented, but design results showing the improvement in structural behaviour are illustrated.