1. Ph.D. Student, Dept. of Building and Precasting, School of Civil Engineering, Polytechnic Univ. of Madrid, E.T.S. de Ingenieros de Caminos, Canales y Puertos, Prof Aranguren S/N, 28040, Madrid, Spain (corresponding author).
2. Full Professor, Dept. of Building and Precasting, School of Civil Engineering, Polytechnic Univ. of Madrid, E.T.S. de Ingenieros de Caminos, Canales y Puertos, c/ Prof Aranguren S/N, 28040, Madrid, Spain.
3. Professor, Dept. of Building and Precasting, School of Civil Engineering, Polytechnic Univ. of Madrid, E.T.S. de Ingenieros de Caminos, Canales y Puertos, c/ Prof Aranguren S/N, 28040, Madrid, Spain.