Predictions of nonlinear fracture process zone in concrete

Crack propagation in concrete is associated with a nonlinear zone around the crack-tip. The size of this fracture process zone length may be large depending upon the size of the aggregates and the geometry of the specimen. A theoretical model to predict the extent of this nonlinear zone and a method to include the effects of this nonlinearity in predicting the fracture resistance of concrete are described. The model is based on some simple and approximate extensions of the concepts of linear elastic fracture mechanics. The model is successfully used to analyze the results of the experiments on double cantilever, double torsion and the notched-beam specimens.