Micromechanical theory and uniaxial tensile tests of fiber reinforced cement composites

The mechanism of fracture arrest in brittle-matrix composites with strong, long fibers is analyzed by using the inclusion method. The maximum stress contribution of the matrix in composites is discussed in this paper. A critical volume fraction of fibersf_cis theoretically derived. If the volume fractionfis less thanf_c, then debonding between fibers and matrix occurs before the crack propagates through the whole section. Iffis greater thanf_c, then no debonding occurs before the crack propagates through the whole section. The value off_cdepends on the matrix and fiber properties and the bond character of the interface. To verify the analytical predictions, experiments on fiber reinforced cement composites subjected to uniaxial tension were conducted. The results of the theoretical predictions were also compared satisfactorily with other published experimental data.