Abstract:Ultra-high-performance concrete (UHPC) is a relatively new class of composite material characterized with its ultra-high strength, high toughness and high durability. There is no design standard about the bonding performance of UHPC with prestressed strands, which is rather different from that of ordinary concrete. Therefore, based on the study on the central drawing tests of 36 UHPC with stranded strands under normal temperature natural curing, with bonding length and thickness of protective layer the research parameters, the load slip curves, failure modes and bond strength have thus been obtained. The analysis and test data show that the ultimate bond stress between UHPC and strand is 7.01~11.65 MPa with an average value of 8.78 MPa, which is obviously superior to ordinary concrete. When the thickness of protective layer of steel strands with a diameter of 15.2 mm is greater than 30 mm, the thickness of protective layer has little effect on the bonding strength. Compared with that of ordinary concrete, the transfer length and anchorage length of 1×7 strand in UHPC can be reduced by 50%. It is recommended that for UHPC with a compressive strength greater than 150 MPa, the transfer length of steel strands should be 25d and the anchorage length 35d.