Experimental and numerical investigation of flexural behavior of hybrid fiber reinforced high strength incorporating binary and ternary blend of ultra fines

Abstract

Hybrid Fiber-reinforced High Strength Concrete (HFHSC) with superior ductile and durable properties is an advanced concrete material for structural applications. The inherent flaw of micro-crack development during the hardening of concrete was addressed by hybrid fibers (micro and macro fibers) for better mechanical and structural performance. However, the behavior of structural members of high-strength concrete with hybrid fiber in a combination of binary and ternary blend of ultrafine filler still needs to be explored. Therefore, current research work was planned to investigate the flexural behavior of hybrid fiber (steel/Polyvinyl alcoholic fiber) reinforced concrete incorporating a binary and ternary combination of ultrafine fillers (i.e., Ultrafine Quartz filler, silica fume, fly ash). The mechanical properties of HFHSC were evaluated. Full-scale beams with HFHSC incorporating different binary and ternary mixtures of ultrafine were cast and tested for flexural behavior evaluation. A numerical simulation of the tested specimen was carried out to predict the flexural behavior of HFHSC. Test results revealed that the flexural behavior of beams incorporating hybrid fiber showed significant improvement in the initial crack strength, ductility, and deflection capacity compared to control beams without fibers. Results showed an increase of around 5% and 50% in load carrying capacity and ductility, respectively, with the addition of hybrid fibers. The results from the numerical model were in good agreement with experimental load carrying capacity and moment capacity predicted by using the concrete damage plasticity CDP model. Hence, it can be deduced that high-strength concrete using hybrid fibers can be used in the construction industry for enhanced structural performance with smaller cross-sectional members leading to reduced structural weight and more clear space.