부산대학교 도서관

The application of ultra-high performance concrete (UHPC) in prefabricated steel-concrete composite beams can produce lightweight prefabricated hollow bridge decks, which is conducive to improving the flexural properties, material utilization, and durability of composite beams. The prefabricated hollow UHPC bridge deck with hollow steel tube was proposed and applied to the flexural test of three composite beams to analyze the influence of hollow steel tube and minimum UHPC layer thickness on the flexural properties. The results show that the prefabricated steel-UHPC composite beam with hollow bridge deck has excellent flexural properties and material utilization, and its failure mode is typical flexural failure. Replacing PVC tubes with hollow steel tubes increases the flexural capacity and stiffness of composite beams by less than 2.43 %, and the ductility coefficient is increased by 13.14 %. The sudden drop in the flexural capacity caused by UHPC crushing at the top of the hollow steel tube can be avoided when the hollow steel tube thickness exceeds 3 mm. The flexural capacity and stiffness of the composite beam are increased by more than 5.56 %, and the ductility coefficient is increased by 7.58 % when minimum UHPC layer thickness is increased from 20 mm to 30 mm. Local crushing will not occur at the top of the bridge deck corresponding to the hollow steel tube when the minimum UHPC layer thickness exceeds 40 mm. Finally, flexural capacity formulas under four section types are proposed based on the simplified method. Deviation between the predicted and test results is within 4.76 %, which confirms the reliability of flexural capacity formula.