1. Dept. of Civil Engineering, Higher Polytechnic School, Univ. of Burgos, C/Villadiego s/n, 09001 Burgos, Spain.
2. Associate Professor, Dept. of Materials and Environment, Faculty of Civil Engineering and Geosciences, Delft Univ. of Technology, Stevinweg 1, 2628 CN, Delft, Netherlands (corresponding author).
3. Professor and Director, Construction Materials Group, Technische Universität Darmstadt, Franziska-Braun Straße 3, 64287 Darmstadt, Germany.