Service Performance of HPSFRC Suitable for Super-High Vertical Pumping

A type of small-scale fibers with dumbbells on two ends and notches in the middle was first designed to improve the workability and crack resistance of fresh high performance steel fiber reinforced concrete (HPSFRC). By using the fiber, the HPSFRC was continuously pumped to 306 meter high Sutong bridge tower. To ensure crack resistance of HPSFRC, tests concerning both non-loaded crack and structural crack were systematically performed, respectively. Then, the mechanisms behind the macro-behaviors were explored. Finally, life assessment method of HPSFRC that focused on the fatigue loading coupled with chloride and carbonation environment was presented by considering the effects of different fatigue degree on concrete durability. The results demonstrate that the steel fiber has the remarkable ability to restrain shrinkage and resist structural crack. It was also shown that the small-scale steel fiber can greatly improve the fracture toughness and fatigue property. In addition, the increased degree of damage due to fatigue loading would shorten the service life of concrete and the service life of HPSFRC under the multi-damage of fatigue loading and environmental loading would be longer than that of plain concrete.