Experimental and Numerical Characterization of Normal-Weight Concrete at the Mesoscale

Modeling the postpeak behavior of brittle materials like concrete remains a challenge from the point of view of computational mechanics due to the strong nonlinearities arising in the material behavior during softening and the complexity of the yield criterion that may describe their deformation capacity under generic triaxial stress states. A numerical model for plain concrete in compression is formulated within the framework of the coupled elastoplastic damage theory. The aim is to simulate, via the finite-element (FE) method, the stress-strain behavior of concrete at the mesoscale, where local confinement effects generally characterize the cement paste under the action of the surrounding aggregates. The mechanical characterization of the components are accomplished through a specific experimental campaign. With the subsequent validation study, it is shown that a few calibration parameters give a good prediction of the material strength and deformation capacity encountered in real uniaxial compression tests.