PREDICTION MODEL FOR ELASTIC-MODULUS OF HIGH-PERFORMANCE FIBER-REINFORCED CEMENT-BASED COMPOSITES

An extensive evaluation of 17 existing analytical models predicting th e elastic modulus of fiber reinforced composites showed that none of t he models is adequate to account for two important factors that greatl y influence elastic modulus of fiber reinforced cement-based composite s. These two factors are bond and matrix porosity. Moreover; finite el ement analysis of a composite unit cell revealed that elastic modulus decreases with a decrease in fiber bonded length, and that fiber end c onditions (with and without end stress transfer capability) are critic al, especially for high fiber-to-matrix moduli ratios. To account for the newly identified variables, namely, bond at the fiber-matrix inter face and porosity of the matrix a semirational prediction model is pro posed and shown to be in good agreement with experimental observations on slurry infiltrated fiber concrete (SIFCON).