Investigation of tensile creep for Ultra-High-Performance Fiber Reinforced Concrete (UHPFRC) for the long-term

The research presented in this paper is associated with the time-dependent tensile behavior of UHPFRC, especially on tensile creep for the long-term. This study outlines the experimental program for the implication of the newly developed testing rig, installation and preparation of test specimens, and studies of the research findings. The time-dependent tensile behavior was evaluated in terms of tensile creep under different sustained tensile loads. The sustained tensile loads were harnessed following the different percentages (50% and 75%) of cracking loads. The cracking loads were determined from the instantaneous tensile tests of unreinforced UHPFRC prism specimens at 28-day. A newly designed test rig was introduced to perform the tensile creep test for the long-term, and the test rig was designed in a way to overcome limitations found throughout the critical literature review. This study demonstrates that the tensile creep of UHPFRC is significantly influenced by the shrinkage strain. The experimental results demonstrate that under higher sustained tensile stress directs to a higher tensile creep rate for the first 13 days. Afterward, the total tensile creep strain was dominated by the shrinkage strain.