NUMERICAL AND EXPERIMENTAL ANALYSIS OF CRACKS AND FAILURE MODE OF CONCRETE BLOCK PRISMS

This paper presents a comparison between experimental and numerical analysis of concrete block prisms under compressive loads. The main goal of the study is to compare damage obtained using a numerical non-local damage model specially developed for quasi-brittle materials with the cracks observed in an experimental program. First, blocks and mortar specimens are submitted to compression and direct tension tests in order to identify their damage parameters. Then, prisms are also tested to evaluate their behavior. All the tests are carried out with displacement control to obtain the complete load-displacement diagram for the specimens: the initial linear behavior, the failure load and the post-peak softening branch. After the experimental program, numerical models are developed, using eight-node ‘brick’ finite elements with secant stiffness matrix. An increasing displacement is applied to the model to simulate the tests. Finally, the cracks and failure mode obtained experimentally are compared with a scalar measure of the damage obtained with the numerical models. Obtained results show that the non-local damage model considered in this paper is able to predict the cracks and even the failure mode of the prisms observed in the experiments.