The realization process of civil engineering structures is complicated: a wide variety of disciplines is involved, each with a specific contribution, and each involved somewhere between initial concept and completion. It is a challenge to structure the process in such a way that a balanced and optimized participation of the many disciplines involved is achieved.
One of the critical success factors is knowledge management: each discipline should bring professional knowledge, but disciplines should interact effectively at interfaces as well. And that is where the gap in practice often appears. Temporary structures for civil engineering projects are an example of this phenomenon; they are right in the middle of a complex system of interactions: between structural engineering, site engineering, work preparation, procurement, and execution. They have a significant impact on cost, construction time, construction methodology and through-life performance of the actual, permanent structure.
Formwork and falsework are among the most important elements of temporary structures for civil engineering projects. And so is the interaction with the many disciplines mentioned before. Knowledge management with respect to formwork and falsework requires engineers to shareknowledge and experience in the broadest sense. As actual performance of formwork and falsework can only be noted at a late stage in the realization process when some disciplines (although in strong interaction with formwork and falsework) are no longer present, the learning circle can only be closed by feedback.
And that is where also a gap appears in practice: as experienced site managers generally know what kind of problems they will face and how to solve them and most site engineers have their lessons learned, it is not common to prepare documents which address practical construction issues in relation to design and application of formwork and falsework, although these documents are a vital link in the learning cycle. Moreover it is not common to include the participation of technical commissions and/or scientific associations in these issues This fib bulletin intends to feedback effectively state of the art knowledge and experience with regard to formwork and falsework. As such it hopes to bridge the gap that often is experienced in practice and to make a larger group of engineers familiar with the important issues related to design and application of formwork and falsework.
This should lead to a better interaction between engineering disciplines involved, resulting in safe, effective and efficient temporary structures. Although commonly applied definitions for formwork and falsework have been used, the authors are aware of the fact that in practice a clear distinction between both elements (form and support) may be difficult as both functions are sometimes integrated. This document addresses some fundamental issues related to formwork and falsework:
• The appearance of the finished concrete which is closely related with the quality of the formwork. Owners/clients tend to be more demanding in this respect.
• The performance of the finished concrete in related to durability and as part of Life Cycle Management. A stronger focus on reliability of (life cycle) performance is noticeable (performance-based building, integrated contracts, through life analysis, etc.).
• The need to support the concrete while it acquires enough strength and stiffness to support itself. In this context the most important issue is structural safety.
Around the world, serious accidents of important civil structures and buildings under construction happened with catastrophic consequences caused by temporary work failure. Accidents during construction are too frequent and society does not accept that exposure anymore. Unfortunately there is a lack of documentation about these events.
This bulletin gives guidance for the design and use of formwork and falsework on construction sites. These guidelines are based on the experience of site and design engineers; and most of the advice has beengiven as a consequence of real problems in the past. Any warnings based solely on theoretical judgement have been avoided; only recommendations based on experience have been included
. This bulletin focuses on principles only and as such does not address detailed design issues, as local design codes should be applied. As construction habits and details sometimes differ from country to country, some advice or recommendations included in this document may be affected by local circumstances.
This Guide to Good Practice represents a summary of the relevant knowledge available to and possessed by the members of Task Group 10.2, and other contributors as listed. The draft report has been discussed and approved by Commission 10 and subsequently released for approval by the Technical Council of fib. Formal approval by the Technical Council of fib was given in May 2008.
I would like to thank all the members of Task Group 10.2 and Commission 10, all the individual contributors from outside Commission 10, and the reviewers of the Technical Council of fib for their contribution to this Guide to Good Practice. In particular, I would like to thank José Emilio Herrero Beneítez, who, apart from his own contribution, did the editorial work for this bulletin.