Fibre factors governing the fresh and hardened properties of steel FRC

Abstract

The concrete mix design of fibre reinforced concrete (FRC) is still largely carried out by a trial and error process of repeatedly conducting trial concrete mixing. Such trial and error process is very slow and sometimes frustrating because the required performance may not be achieved even after many trials. In this study, the effects of the fibre content and characteristics on the fresh and hardened properties of steel FRC have been evaluated by testing and the measured properties have been correlated by regression analysis to the various fibre factors to identify the fibre factor governing each performance attribute. The correlations revealed that the traditional practice of taking the fibre factor as the fibre volume times the aspect ratio is overly simplistic and that the fibre number is more fundamental than the fibre volume. Moreover, based on the correlations, design equations for predicting the various performance attributes have been derived for the mix design of steel FRC.