Numerical 2d investigation of non-metallic (glass, carbon) fiber micro-mechanical behavior in concrete matrix

In the paper short glass and carbon fiber micro-mechanics in concrete matrix is under consideration. Investigated were one fiber or fibre bundle pullout dynamics as well micro-stresses in the material. During performed single fiber and single bundle pull out experiments were established such process mains steps: a) fiber and matrix elastic deformation with perfect bond between fibre and matrix; b) cylindrical delamination crack growth in material between fibre and concrete matrix; c) fibre break in concrete, after what free fiber end with friction is pulling out of matrix. Numerical model based on FEM were elaborated for all three failure steps. Numerical simulations were established mechanical background for such failure phenomena. Similar way numerical models were elaborated and exploited for fibre bundles and single fibers were embedded into concrete under angle to pull out force direction. Were established main load bearing and failure mechanism for short glass and carbon fiber concrete composites - single fibre and fibre bundles pull out with simultaneous fibre failure in outer bundles shell.