1. ISF–Welding and Joining Institute, RWTH-Aachen Univ., Pontstrasse 49, 52062 Aachen, Germany.
2. Rhein-Chemotechnik, Gewerbepark Siebenmorgen 8, 53547 Breitscheid, Germany.
3. Professor, Institute for Building Materials Research (ibac), RWTH-Aachen Univ., Schinkelstraße 3, 52062 Aachen, Germany.
4. Professor, ISF–Welding and Joining Institute, RWTH-Aachen Univ., Pontstrasse 49, 52062 Aachen, Germany.