ABSTRACT
A micromechanical model is presented for the uniaxial compressive strength of fiber reinforced cementitious composites (FRCC). The model is based on the classical models of compressive failure of brittle solids containing sliding microcracks that induce wing-crack growth under compressive loading. The concepts of increased microcrack sliding resistance and wing-crack growth retardation associated with fiber bridging are exploited to produce a strengthening effect of fibers on composite strength. The concept of defect introduction associated with fiber volume fraction is included to produce a composite strength degradation. The combined effects result in a composite compressive strength which increases initially and subsequently drops with increasing fiber content, as has been observed in FRCs reinforced with a variety of fibers. This paper represents an extension of a preliminary study of the influence of fibers on compressive strength of FRCC by Li (1991). More accurate stress intensity factor calibrations for wing-crack growth and interaction are employed in the present paper. The predicted general trends of compressive strength change with fiber parameters remain unchanged from the original work.
