EVALUATION OF WORKABILITY PARAMETERS FOR HOOKED-END HIGH STRENGTH STEEL FIBER CONCRETE MIXES

Abstract

Discreet discontinuous steel fibers have been found useful in concrete construction. However, their workability present challenges, especially at high volume fraction (V-f). In this study, workability of high strength steel fiber concrete (HSSFC) was evaluated for three hooked-end steel fibers with different aspect ratios of 60, 75 and 83 and at different fiber volume (V-f) of 0.0, 0.5, 1.0, 1.25, 1.5, 1.75 and 2.0 %. The purpose of this study was to establish relationships among the relevant variables through examining their workability test results. Regression models were developed and validated using fiber reinforcement index (FRI). Findings revealed that with an increasing FRI, VeBe time increases exponentially, slump and compacting factor decreases linearly. More so an inverse relationship was observed between yield stress and slump. Regression models were closer to unity, which indicates a strong correlation between FRI and workability parameters with the exception of compacting factor. In order to obtain a valid correlation, it is hereby suggested that a combination of tests should be considered to fully characterize the workability parameters.