Coordinator

Thomas Misiek, Breinlinger Ingenieure, Germany

Background Inofromation

The European Joint Committee on Sandwich Constructions combines two working groups: CIB W056 “Sandwich Panels” and ECCS TC7 TWG 7.9 “Sandwich Panels and Related Structures”.

The CIB W056 committee was established in 1971 as CIB Steering Group S56. The ECCS Technical Working Group TWG 7.4 was established in 1983 to develop European recommendations for design, testing and good practice for the use of sandwich panels with metallic faces. Today, the later Technical Working Group ECCS TC7 TWG 7.9 and the Working Committee CIB W056 provide a powerful forum for the dissemination and practical application of international research and development of design and testing of sandwich panels. A brief history of the Joint Committee can be found in:

Davies, JM, Hassinen, P., Heselius, L., Misiek, Th.: ECCS/CIB joint committee on sandwich constructions: Recent European Recommendations on design and testing. CIB World Congress 2010. Proceedings, University of Salford, UK, 2010 (http://www.irbnet.de/daten/iconda/CIB18791.pdf)

The members represent universities, manufacturers, consulting engineers and industry associations from several European countries and Australia.

Objectives and Scopes

The commission deals with sandwich panels – i.e., structural elements consisting of a light-weight core material and two faces – and their application in buildings. The focus is on topics such as mechanical strength, design, detailing and construction, but also related topics such as fastenings of sandwich panels or stabilisation of other structural components by sandwich panels. On these topics, the Commission publishes so-called “recommendations”.

Topics such as building physics, acoustic or fire are discussed within the Commission, but play a subordinate role, especially in connection with the Commission’s publications.

The European Recommendations (ERs) published by the Commission deal with the design and detailing of sandwich panels in application areas that are not yet covered by standards, guidelines etc. They are often seen as pre-normative publications that help to develop ENs. ERs published so far cover topics such as

  • Actions and loads on sandwich panels
  • Special applications, e.g.: sandwich panels with openings or under axial force

Recent Publications:

Preliminary European Recommendations for the Design of Sandwich Panels with Openings. CIB Publication 378/ECCS Publication 134, 2013

European Recommendations on the Stabilization of Steel Structures by Sandwich Panels. CIB Publication 379/ECCS Publication 135, 2014

European Recommendations for the Determination of Loads and Actions on Sandwich Panels. CIB Publication 404/ECCS Publication 136, 2015

European Recommendations for the Design, Detailing and Application of Fastenings for Sandwich Panels. CIB Publication 418/ECCS Publication 142, 2019

Current Work Programme and Planned Output

European Recommendations (ER) on experimentally based Determination of Rotational Restraint provided by Sandwich panels

The building envelope made of sandwich panels can be used to stabilize the supporting structure. This enables a lighter and thus more economical design of the supporting structure. The interaction is quite complex, because the deformations of the supporting structure, the flexibility of the fastenings, etc. have to be taken into account. One therefore often has to rely on experiments. However, harmonized provisions for set-ups, conduction and evaluation of these tests have been lacking so far, i.e. the available information is based on different procedures. The ER covers the following topics:

  • Basics of the mechanisms of rotational restraint
  • Description of various test set-ups used in the past, their assessment
  • Comments on the test setup according to EN 14509-4 (which is practically the future state of the art)
  • Description of evaluation of tests
  • Example evaluation of tests

Scheduled date of publication is beginning to mid of 2023.

European Recommendations (ER) for the Design of Sandwich panels with Point and Line Loads

This ER is generally about fastening to sandwich panels, e.g. of

  • additional facades to satisfy higher demands on the visual appearance
  • PV modules on sandwich panel roofs

These are no trivial problems due to the thin face thickness (approx. 0.5 mm) and the bonding to the core of insulation material. In addition, there are load-bearing mechanisms (e.g., lateral distribution of point loads, torsion) that are not covered by the existing design provisions. The ER closes this gap by covering the following topics:

  • Loads specific for these applications
  • Mechanical modelling for these applications: “deep beams”, point loads, torsion,
  • Design verifications for the panels and the fastenings
  • Design Examples
  • Tests for determination of specific parameters (stiffnesses, resistances)

Scheduled date of publication is mid of 2023.

European Recommendations (ER) for the Design of Sandwich panels under Axial loads:

Sandwich panels were originally developed as structural elements for a building envelope which is subject to bending due to wind, snow, etc. Sandwich panels are also used as walls for cold storage cells inside a building, where no wind and snow loads occur. In this case, a load-bearing structure is mostly dispensed with. The sandwich panels of the walls must then transfer axial compressive forces.

As a new development, both areas of application are combined: in smaller buildings, the envelope then takes over the load-bearing function.

In this case, a design of the sandwich panels is required that also takes into account the interaction of transverse load and axial load. The ER explains the design.

A date of publication has not yet been set.

External Relations

W056 has joint activities with ECCS TC7

Membership

Members of this Working Commission have to be either a Representative of a CIB Member Organisation or an Individual CIB Member, or they have to be appointed as Commission Member by ECCS.

Status

W056 is a joint commission of CIB and ECCS – The European Convention for Construction Steelwork https://www.steelconstruct.com/