1. Institute of Construction and Building Materials, Technical University of Darmstadt, Franziska-Braun-Str. 3, Darmstadt 64287, Germany
2. Univ. Lille, IMT Nord Europe, JUNIA, Univ. Artois, ULR 4515-LGCgE, Laboratoire de Génie Civil et géo-Environnement, Lille F-59000, France