REINFORCEMENT OF MORTAR WITH METGLAS FIBERS

An alkali resistant Metglas fibre of composition Fe29Ni49P14B6Si2 was used in 2.5cm lengths as discontinuous reinforcement for mortar. The force-displacement curves for pull-out of roughened individual fibres embedded into mortar were measured. Composite experiments with fibres in planar random orientations have demonstrated that the first crack strength rises weakly with increasing fibre volume fraction according to the principle of non-propagating cracks. The maximum post cracking strength rises linearly with increasing volume fraction up to Vf=0.012 where it levels off due to secondary fragmentation in the matrix. The monotonic fracture behaviour of the material in nearly all respects is in accord with theoretical expectations. Under cyclic conditions, the composite undergoes progressive damage only when the maximum tensile stress per cycle penetrates beyond a critical amount into the range between the first crack strength and the maximum post-cracking strength. © 1979 Chapman and Hall Ltd.