Inhomogeneous fibre matrix

Comparing these data it may be seen that they agree within the limits of the error of measurements, except for the stiffness modulus 31 the measured value of which is higher than the one calculated from equation (25) by as much as 22%. We suppose that this is due to the fact that equation (25) is not adequate for this material, where regions of a weak adherence of fibres to the matrix probably occur. The effect of such inhomogeneities upon the stress concentration and deformation has been discussed before for polycrystalline graphite. 

Means taken to reduce the size and inhomogeneity of the ITZ will lead to its strengthening and the expected result is an overall increase in bond, as demonstrated by Igarashi eta/. [45] the bond of steel fibre to a paste matrix increased with mixing time 0.7, 1.0 and 1.3 MPa of average bond for 0, 20 and 40 min of agitation of the mortar matrix against the fibre (Table 3.4). 

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