Title:
Fracture Model to Predict Stress Intensity in Fiber Reinforced Concrete
Author(s):
Sameer A. Hamoush, M. Reza Salami, and E. A. Abu-Saba
Publication:
Materials Journal
Volume:
88
Issue:
5
Appears on pages(s):
504-507
Keywords:
cracking (fracturing);fiber reinforced concretes; flanges; fracture properties; mathematical models; pullout tests; stresses; Materials Research
DOI:
10.14359/2162
Date:
9/1/1991
Abstract:
A fracture model is developed to predict the stress intensity factor of fiber reinforced cementitious composites. The model accounts for the fiber bridging the crack faces in the crack-tip zone. The proposed model is based on the superposition technique in fracture mechanics in conjunction with an existing pullout model for the fiber pulling out of the concrete. The pullout model is based on an axisymmetric representation of the fiber pulling out of the concrete. The proposed fracture model assumes that the final slip distance of the fibers equals the final crack flange opening displacement. The final crack flange opening displacement equals the opening of the flanges, ignoring the fibers' contribution and the arrests caused by the fibers. In this model, two basic steps are used in the solution procedure. The first step is to ignore the contribution of the fiber and find the crack flange displacement at the location of the fibers. The second step is to find the crack flange displacement due to one unit of force at each fiber location. The compatibility condition is employed to find the final pullout force in each fiber. Attention is focused on the compatibility conditions with the fiber pullout displacement included. The forces in pulled-out fibers are restricted to the capacity of the fiber. In this paper, the example problem is a plate with an edge notch subjected to far-end normal stress. The analytical solution for a homogeneous plate with edge notch is given in the literature. This paper assumes uniform distribution of the fibers that are perpendicular to the crack face. For more general problems where the fibers are randomly distributed and the analytical solutions are not available for the homogeneous body, numerical solutions including statistical functions must be used.