Mechanics of fibre reinforced cementitious composites

I n FRC composites, the major role played by the fibres occurs in the post-cracking zone, in which the fibres bridge across the cracked matrix. In a well-designed composite the fibres can serve two functions in this zone  

1 They may increase the strength of the composite over that of the matrix, by providing a means of transferring stresses and loads across cracks. This i mp I i es an ascend i ng stress-strai n curve after first cracki ng, and this behaviour 

1 Elastic range , up to the point of first crack the matrix and the fibres are both in their linear, elastic range. 

2 Multiple cracking range, in which the composite strain has exceeded the ultimate strain of the matrix. 

3 Post-multiple cracking range, during which the fibres are being stretched or pulled out of the cracked matrix. 

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