Bending and shear resistance of prestressed UHPC-RC composite beams without web reinforcements

In order to explore the shear mechanical performance of UHPC-RC beams without web reinforcements, the paper conducted 15 full-scale UHPC-RC non web reinforced beam shear tests, systematically studied the influence of key structural parameters such as shear span ratio, web plate thickness, steel fiber content, and compressive stress level on the shear performance of UHPC-RC non web reinforced beams. Based on the modified pressure field theory and the idea of sub item superposition, a shear bearing capacity calculation model was established that comprehensively considers the top plate compression shear zone, web plate oblique shear zone, and bottom plate tensile shear zone. Comparison with experimental results shows that the shear calculation method in this paper can accurately calculate the shear bearing capacity. Shear bearing capacity of pre-stressed UHPC-RC composite beams without belly reinforcement. The analysis of experimental parameters shows that the ultimate shear bearing capacity of UHPC-RC beams without web reinforcement decreases with the increase of shear span ratio: The content of steel fiber has a certain impact on its ultimate shear bearing capacity: The ultimate shear bearing capacity increases with the increase of web thickness: The ultimate shear bearing capacity increases with the increase of compressive stress level: Applying prestress can improve the shear ultimate bearing capacity and initial stiffness of the structure.