关键词：高强度混凝土；钢绞线;桥梁；纤维增强混凝土
摘 要：The development length of reinforcements embedded into ultra-high performance concrete (UHPC) can be significantly shorter than the lengths normally associated with conventional concrete. Shortening the development length of prestressing strand can allow for a redesign of some structural systems, including spliced girder and continuous-for-live-load bridges. Ultra-high performance concrete (UHPC), when used in field-cast connections between prefabricated bridge elements, can create robust connections which emulate monolithic components. This study investigated the development length of 0.5 and 0.6 inch (12.7 and 15.2 mm) diameter untensioned prestressing strands embedded in steel fiber and PVA fiber reinforced UHPC. The volumetric fiber content was 2 percent. A novel tension test method allowed for replication of the tension-tension stress state that would occur when two strands are lap spliced within a connection between two linear elements. The results suggest that, for the steel fiber reinforced UHPC, the 0.5 inch (12.7 mm) diameter strands can be fully developed within 20 inches (0.51 m) and the 0.6 inch (15.2 mm) diameter strands can be fully developed in approximately 24 inches (0.61 m). The 0.5 inch (12.7 mm) diameter strands can be fully developed in the PVA fiber reinforced UHPC in approximately 36 inches (0.91 m).