Experimental and Numerical Investigation of Single Fiber Pull-Out Tests of Steel Macro-Fiber and Glass Micro-Fiber in a Cementitious Matrix

Abstract

This paper presents a modeling-based relationship between fiber diameter and frictional bond strength for steel macro-fiber (0.8-mm diameter) and glass micro-fiber (5-24-mu m diameter) embedded in a cementitious matrix. A combined approach of experimental stress-displacement results obtained through single fiber pull-out tests and finite element modeling (FEM)-based stress-displacement results yielded the friction coefficient for the two types of fibers used. Further analysis relating to the pressure exerted on the fiber caused by the surrounding concrete reveals that a smaller fiber diameter would improve the bond strength. The improvements in frictional bond strength due to reduced diameter are based on FEM analysis. Validation of the experimental results is done through numerical approaches. The results showed that in the case of the same diameter, the pressure of the surrounding concrete decreases throughout the fiber sliding. The results also showed that the smaller diameter of fiber improves the properties of fiber-reinforced concrete interfaces.