Flexural strength and toughness of self-leveling UHPFRC

Abstract

Acquiring higher performance at both fresh and hardened states is critical in the practical design of ultra-high performance concrete (UHPC)/ultra-high performance fiber reinforced concrete (UHPFRC). Herein, a total of 12 self-leveling UHPC and UHPFRC mixtures were developed and evaluated for their flexural performance by three-point bending tests, together with their workability and mechanical properties. From load-deflection curves, the first cracking flexural strength, post cracking flexural strength, flexural deflection capacity, and flexural toughness were determined. By corelating the flexural responses to fiber factor and matrix strength, the flexural strengths were found to be positively affected by fiber factor and matrix strength, while the flexural deflection capacity and toughness indices were less influenced by matrix strength but can be substantially enhanced by increasing steel fiber volume. Design equations were derived by physics-informed data-fitting for flexural strengths and toughness with high accuracy, allowing for quantification of synergistic effect between fiber factor and matrix strength in resilient design.