Evaluating the Filling Performance of Steel Fiber-Reinforced Self-Compacted Mortar into Rock-Filled Concrete

ABSTRACT Adding fiber segments to a concrete mix design could influence the rheological properties of the mortar. In this study, the filling performance of steel fiber-reinforced self-compacted mortar (SFRSCM) into granular packs is investigated to produce steel fiber-reinforced rock-filled concrete. This investigation considers using steel fiber segments with different fiber aspect ratios and fiber volume fractions using the OpenFOAM computational fluid dynamics program. For this purpose, the Interfoam solver, which can simulate SCM flow, had to be upgraded to accurately characterize the motion of the fiber segments and calibrate it with experimental and numerical data from the literature. This study demonstrated that the SCM flow without fiber reinforcement has a better filling performance than the SFRSCM flow. In addition, new relations are proposed to describe the effects of the addition of fiber segments on the rheological properties of SCM. The results demonstrated a strong correlation between the proposed equations and their practical application. Furthermore, a general equation was proposed and validated by using cases from the literature, indicating its efficacy in predicting yield stress for various mixture designs with diverse fiber diameters and volume fractions. This implies that these equations may be used in future research and within the construction industry. Specifically, they could be used in mix design to adjust the amount of steel fiber segments while preserving the flowability characteristics of the SCM.