Improving reinforcement of cement-based composite continuous beam using adaptively distributed steel fibers

To maximize the reinforcement of steel fibers in cement-based composite specimens, both the orientation and volume fraction of the steel fibers were optimized according to the principal tensile stress everywhere in the specimen, which is defined as Adaptively Distributed Steel Fiber Reinforced Cement-based Composites (ADSFRC). In this investigation, the steel fibers in AD-SFRC 2-span continuous beams were optimized, and the specimens were prepared and tested. The distribution of steel fibers, including both orientation and dosage, throughout the specimen was determined according to the principal tensile stress. In the preparation of AD-SFRC 2-span continuous beam, the orientation of steel fibers in the beam was aligned by applying electromagnetic field, and the volume fraction of steel fiber was adjusted by casting specimen section by section and layer by layer. Finally, the flexural properties of the 2-span continuous beam subjected to midspan loading were tested and compared with that of specimens with random and other types of steel fiber distribution. The results show that the cracking load, ultimate load and flexural toughness of AD-SFRC specimens are significantly improved.