Surface Properties of a Hooked Steel Fiber and their Effects on the Fiber Pullout and Composite Cracking 1. Experimental Study

Abstract

Concrete as a material is brittle, but adding short steel fibers to the matrix can significantly improve its mechanical properties. The chemical adhesion between concrete and steel is weak, and the fiber pullout properties are based on fiber geometry and frictional forces. Single-fiber pullout tests of steel fibers with toothed and smooth surfaces were performed in order to characterize the effects of fiber surface facture. The influence of fiber form, surface facture, and fiber orientation (relative to the pullout direction) on the fiber withdrawal resistance and the maximum pullout force were studied.