FAILURE MECHANISMS OF STEEL FIBERS EMBEDDED IN HSFRSCC
Luiz Carlos De AlmeidaChestnut
The bond stress transfer between fibers and matrix is the basic resistant mechanism of fiber-reinforced composite materials. Interfacial bond properties and failure mechanisms of the composite are commonly evaluated through single pullout tests on unreinforced matrices. The small size of the molds used to cast the samples prevents the fibers from being randomly distributed in the matrix and makes it difficult to compact the mixture. Krahl et al. (2020) developed an innovative portable pullout machine that allows testing fibers embedded in fiber-reinforced matrices with larger sample sizes. This paper discusses the experimental results of single fiber pullout tests carried out with the portable machine on high-strength fiber-reinforced self-compacting concrete (HSFRSCC). The bond behavior of hooked-end steel fibers and their relationship with the failure mechanisms are analyzed for fiber contents of 0% and 0.75%. The results show that bond and failure mechanisms were influenced by the presence of fibers in the matrix.