Research on the Effect of Fiber Content on the Fiber Bridging Stress in Ultra-high Performance Concrete
To ensure the effect of fiber bridging stress is reasonably considered in crack width calculations for structures using Ultra High Performance Concrete(UHPC),specimens with notched dog-bone shapes and fiber contents of 1%,2%,and 3%were designed.Axial tensile tests were conducted on UHPC materials to determine the development of fiber bridging stress for different tensile performance grades of UHPC and the impact of fiber content on the fiber bridging stress of UHPC.The results indicate that:1)Within the fiber dosage range from 1%to 3%,the macro-cracking strength,tensile peak strength,fiber bridging stress,and crack control capacity of UHPC materials all increase with the increase of fiber content;2)For UHPC materials with the same fiber characteristics,the maximum crack width that can be bridged by fibers is basically same;3)Both strain-softening and low strain-hardening UHPC exhibit a steep stress drop after cracking,whereas high strain-hardening UHPC does not show such a stress drop.This indicates that high strain-hardening UHPC can achieve smeared cracking without reinforcement,whereas strain-softening and low strain-hardening UHPC require reinforcement to achieve smeared cracking.
ultra-high performance concreteaxial tensile behaviorfiber bridging stresscrack widthaxial tensile test
万方数据
维普
