Effect of sustained loading on the post-creep flexural behavior of cracked hybrid fiber-reinforced concrete

Abstract

Extensive research on fiber-reinforced concrete (FRC) has led to a solid understanding of its structural behavior, enabling the development of design codes. Initially dominated by steel fibers, FRC has progressively incorporated macro synthetic fibers, particularly in Latin America, where it is widely used in tunnel linings. More recently, hybrid FRC, combining different fiber types, has attracted increasing attention due to its improved performance throughout the different stages of crack development. Although its short-term behavior is well established, its response under sustained loading (creep) and its influence on post-creep behavior remain insufficiently understood. This paper presents an experimental evaluation of the post-creep behavior of hybrid FRC, conducted in accordance with RILEM recommendations. The results are compared with those obtained for concrete reinforced with steel fibers and macro synthetic fibers.