24. March 2017

Hung up

Splendid isolation – the GRP-wave, façade fastening of tomorrow

Conventional metal façade fastening elements have a serious drawback; they have to penetrate the insulation and form thermal bridges. The research project addresses this issue by developing a GRP façade fastening element. Within the project “GRP-Wave” the IVW is cooperating with the Institute of Concrete Structures and Structural Engineering of the Technical University of Kaiserslautern and the companies Martin Schwarzenbeck & Co. and Kappema GmbH.


The IVW investigates the effects of different load conditions on the glass fiber reinforced connection element (GRP-Wave, see Figure 1) by means of the finite element method (FEM). The “GRP-Wave” represents the connecting element between the load-bearing inner wall and the façade lining. It forms, as opposed to metallic fasteners, no thermal bridge between both concrete parts.

The particular challenge of the structural analysis of the GRP-Wave by a finite element model is the modeling of the connection between concrete and GRP material.

Since the ends of the rods and the edges of the GRP-Wave are encased in concrete (Figure 2), a suitable material model must be implemented. The material model must take into account both, the contact between GRP and concrete, as well as the plasticity of the concrete or the occurrence of slight concrete cracks due to high loads in the GRP-Wave.

Tests of façade elements carried out at the Institute of Concrete Structures and Structural Engineering demonstrated that the chosen FE-modeling provides realistic values (see Figure 3).


Further information:

TU Kaiserslautern,
Dr.-Ing. Nicole Motsch,
Kompetenzfeldleiterin Bauweisen, Institut für Verbundwerkstoffe (IWU), Kaiserslautern,
Telefon +49 (0) 631 / 20 17-423,

Dipl.-Ing. Arnaud Pavis d’Escurac, M.Eng.,
Wiss. Mitarbeiter, FB Bauingenieurwesen, TU Kaiserslautern
Telefon +49 (0) 631 / 205-30 84,

Jürgen Bauer,
Kappema GmbH,Teisendorf,
Telefon +49 (0) 88 03 / 63 00-120, +49 (0) 152 / 226 99-714,


The project “GRP-Wave“subcontracted by Kappema GmbH supports the ZIM project “Development of structural core insulated doublewall constructions by deploying a novel GRP Wave“ funded by the Federal Ministry of Economic Affairs and Energy based on a decision by the German Bundestag (KF3251301HF3).