Modelling of fibre pull-out from a cement matrix

Abstract

Theoretical analyses of fibre pull-out from a matrix reported in the literature are briefly reviewed. The effects of Poisson's ratio, elastic-frictional bond strengths, and bond strength variation with slippage distance on the pull-out relation are discussed. A theoretical model motivated by observations of fibre surface abrasion is developed to predict the pull-out force versus displacement relationship. The model takes into consideration the variation of the frictional fibre-matrix bond strength with fibre slippage distance. Good agreement is achieved between model predicted pull-out behaviour and experimental pull-out curves for nylon and polypropylene fibres. For these synthetic fibres, the bond strength increases with the slippage distance during the process of pull-out. The model also predicts reasonably well the pull-out behaviour of steel fibres for which the bond strength decreases with the slippage distance.