Title:
Prediction Model for the Elastic Modulus of High-Performance Fiber Reinforced Cement-Based Composites
Author(s):
Husam S. Najm and Antoine E. Naaman
Publication:
Materials Journal
Volume:
92
Issue:
3
Appears on pages(s):
304-314
Keywords:
bond (concrete to reinforcement); fibers; finite element method; modulus of elasticity; porosity; slurries; Materials Research
DOI:
10.14359/1123
Date:
5/1/1995
Abstract:
An extensive evaluation of 17 existing analytical models that predict the elastic modulus of fiber reinforced composites showed that none of the models are adequate enough to account for two important factors that greatly influence the elastic modulus of fiber reinforced cement-based composites. These two factors are bond and matrix porosity. Moreover, the finite element analysis of a composite unit cell revealed that the elastic modulus decreases with a decrease in fiber-bonded length, and that fiber end conditions (with and without end stress transfer capability) are critical, especially for high fiber-to-matrix moduli ratios. To account for the newly identified variables, namely, the bond at the fiber-matrix interface and the porosity of the matrix, a semi-rational prediction model is proposed and is shown to be in good agreement with experimental observations on SIFCON (Slurry Infilitrated Fiber Concrete).