Detalhes do Artigo
[306923] Estimation of the dynamic modulus of elasticity of concrete using contact ultrasonic and impulse excitation methods
Autores: Aline Marçal da Rocha, Ericles William Jesus Santos, Alex Justen Teixeira, Tiago Costa Dourado, Sandro Aureliano Miqueleti, Robson Luis Gaiofatto, Rodrigo Pereira Barretto Costa-Félix
Resumo: It is extremely important to know the mechanical resistance to compression of concrete, precisely because it is related to the safety, quality, and durability of structures. However, when designers find themselves in a modeling stage of a structure, knowledge of the modulus of elasticity is essential. In practical terms, it is possible to estimate this property based on pre-established normative values. This practice, although avoiding costly experimental measurements, can lead to oversizing. For this research, this property was obtained and evaluated based on contact ultrasound tests and compared with the results obtained with the excitation method using the Sonelastic® system. To obtain the dynamic modulus of elasticity, the ultrasonic wave propagation test was used for concrete at 14 and 28 days with compressive strength selected to 20 MPa, 30 MPa, 40 MPa, and 50 MPa. All four mixes were made with the addition of a super plasticizer additive, which obtained the lowest water/cement ratio and dosages according to ABNT NBR 6118:2014 Concreto Armado – Procedimento. A set of 84 samples of cylindrical concrete specimens 100mm in diameter and 20mm in height were cast. The measurements allowed establishing comparisons among themselves between the selected acoustic methods for estimating the dynamic modulus of elasticity, as well as comparing with results of static modulus of elasticity established in ABNT NBR 6118:2014.