This study includes an analysis of the applicability of current models used for estimating the mechanical properties of conventional concrete to self-compacting concrete. The mechanical properties evaluated are: modulus of elasticity, tensile strength, and modulus of rupture. An extensive database which included the dosifications and the mechanical properties of 627 mixtures from 138 different references, was used. The models considered are: ACI, EC-2, NZS 3101:2006 (New Zealand code) and the CSA A23.3-04 (Canadian code). The precision in estimating the modulus of elasticity and tensile strength is acceptable for all models; however, all models are less precise in estimating the modulus of rupture.
Compared with conventional concrete, SCC mixtures generally have higher powder content, high content of high range water reducing agents (HRWRA), lower gravel content, smaller maximum gravel diameter, and a higher paste volume. These modifications in the composition of the mixture affect its behavior in the fresh state, but also its mechanical properties in the hardened state.
It is generally considered that the mechanical properties of SCC and conventional vibrated concrete (CC) are similar. However, the opinions on this subject are various, and further research is still needed. Evaluating numerous studies regarding this topic, it is clear that the conclusions regarding the mechanical properties of SCC in comparison to conventional concrete are not unanimous. For example, Attiogbe et al. [1] concludes in his study that conventional and SCC have equivalent modulus of elasticity. On the other hand, Holschemacher and Klug [2] indicate that the modulus of elasticity of SCC is lower than that of conventional concrete. Regarding the tensile strength, Ouchi et al. [11] reports that SCC and conventional concrete have equivalent tensile strength, while Marti et al. [4] indicates that the tensile strength of SCC is higher. For the modulus of rupture, Leeman and Hoffman [5] determine that it is similar for both concretes, while Turcry et al. [6] found that it is higher for SCC. The differences in the mechanical properties of conventional concrete and SCC can be attributed to three main characteristics of SCC: modifications in the composition of the mixture, improvement of the microstructure of the concrete, and the no vibration of the concrete when poured.