A MESO-SCALE CRACKING-BRIDGING MODEL OF INCLINED FIBER IN STEEL FIBER REINFORCED CEMENTITIOUS COMPOSITES

The crack-bridging behavior of inclined steel fiber in cementitious composites is discussed at meso-scale in this paper. The embedded part of the fiber in the cementitious composites is assumed to act as a bar, while the part of the fiber outside the matrix is simplified into two configurations, cantilever beam for elastic fiber and plastic joint for elastoplastic fiber. The Naaman抯 shear lag model is adopted for the axial control relation. A concept of lateral effective load-bearing area is adopted to simplify the description of the effects of local spalling or crushing in matrix around the fiber. An analytical debonding and pullout model for high modulus inclined fiber is constructed. Results show that the model can preliminarily simulate the elastoplastic pullout behavior of inclined high modulus crack-bridging fiber.