Fiber reinforced concrete has been identified as a particulate composite consisting of hardened cement paste, fine aggregates, coarse aggregates, particulate fibers etc. and each constituent plays a significant role in the combined quasi brittle behaviour of the material. From the view point of a numerical modeler, a two phase model consisting of a matrix phase and a coarse aggregate phase is simple and sufficient enough to take care of the heterogeneity without affecting the capability of the model to predict the material behaviour as reported by Ghouse et al [1]. Thus the unit cell under consideration is modeled as a square with an inner circle (Fig. 1), the square representing the total volume fraction of combined properties of cement paste, fine aggregates, particulate fibers and water. The inner circle represents the total volume fraction of coarse aggregates in the material. This representative volume fraction is assigned with periodic boundary conditions to ensure uniformity in deformation and to avoid any discontinuities in the material once the unit cell has been repeatedly arranged to build up the macro sized material and has undergone deformation in elastic range. Ghouse et al [1] could identify only slight variations in the compressive strength of normal low strength concrete with varying aggregate volume fractions. A comparatively decreasing trend in compressive strength has also been observed initially when glass fiber reinforced high strength cement composite (GFRCC) was analyzed by Sunir et al [2]. Investigations proceed in the direction of predicting the material behaviour by replacing the glass fiber and its volume fraction with polypropylene fibers considered by Pavan [3] as being significant in improving the mechanical characteristics of the macro composite under consideration. An analysis of polymer fiber reinforced high strength concrete (PFRC) with similarly varying aggregate volume fractions could predict significantly decreasing trends in compressive strength for lower volume fractions. In future, the ease with which the unit cell approach predicts the behaviour of fiber reinforced plain mortar is also to be investigated in a similar manner.