FFRC and SASW nondestructive evaluation of concrete strength from early ages Martínez Soto, Fernando Ávila Cruces, Fernando José Puertas García, María Esther Gallego Sevilla, Rafael Universidad de Granada. Grupo de investigación TEP167 Concrete Early-age concrete NDT SASW FFRC Free-Free Resonant Column and Spectral Analysis of Surface Waves are two nondestructive testing techniques which are becoming increasingly relevant in construction engineering, as they offer the possibility of assessing the mechanical properties of the building materials without damaging the sample. In the present study, these two testing methods are applied on concrete samples with increasing curing times, from 9 h to 60 days, estimating the dynamic elastic modulus and proposing relationships to obtain the compressive strength from these values. The nondestructive results are compared with the actual strength of the material obtained via uniaxial compression tests, proving the accuracy of the proposed nondestructive testing methodologies, even for early ages. SASW tests are also carried out on a reinforced concrete sample, concluding that the presence of the reinforcement does not alter the results of the test. Keywords: Concrete; Early-age concrete; NDT; SASW; FFRC 2024-01-23T12:48:00Z 2024-01-23T12:48:00Z 2023-10-01 info:eu-repo/semantics/article Fernando Martínez-Soto, Fernando Ávila, Esther Puertas, Rafael Gallego, FFRC and SASW nondestructive evaluation of concrete strength from early ages, Journal of Building Engineering, Volume 76, 2023, 107093, ISSN 2352-7102, https://doi.org/10.1016/j.jobe.2023.107093. https://hdl.handle.net/10481/87165 https://doi.org/10.1016/j.jobe.2023.107093 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier