1 23 Materials and Structures ISSN 1359-5997 Volume 50 Number 1 Mater Struct (2017) 50:1-17 DOI 10.1617/s11527-016-0875-8 Influence of time-dependent restrained strains in the shear response of RC frames Denise Ferreira, Jesús M. Bairán & Antonio Marí