Microplane model for concrete. Part II. Applications on CFRP confined concrete elements

In the paper the main results of numerical study presented in Gambarelli et al. on concrete elements confined by carbon fiber reinforced polymer (CFRP), are overviewed. Furthermore, preliminary results of numerical simulations performed at mesoscale are presented. The numerical study is based on a extensively experimental campaign conducted by Wang and Wu on small CFRP-confined concrete columns loaded in uni-axial compression. The specimens are characterized by constant size but different cross-section corner radius (from square to circular cross section). The experimental results clearly demonstrate that CFRP confinement is much less effective in square then in circular cross-section. Several numerical models have been performed at macro-scale and meso-scale to confirm the predictability of the used numerical approach, based on the microplane constitutive law for concrete. In the finite element model carbon fibers (truss FE) are embedded into matrix (solid 3D FE). The same as for concrete, the constitutive law for matrix is also based on the microplane model. It is demonstrated that the numerical model is able to predict behavior of confined concrete columns from the experimental investigations. Therefore, the results of the study confirm the predictability of the used numerical approach.