Cracking Resistance of UHPC-NC Structure in Negative Moment Zone of Prestressed Concrete Beam Bridges.

The existing anti-cracking measures in the negative bending moment zone of prestressed concrete beam bridges have many disadvantages. The application of Ultra-high-performance concrete (UHPC) provides a new option for the anti-cracking measures in the negative bending moment zone A prefabricated continuous connection structure of UHPC-NC (normal concrete) with a higher reinforcement ratio in the negative bending moment zone was proposed to improve the cracking resistance in the negative bending moment zone. The cracking load calculation method was given based on theoretical analysis under different loading modes of the UHPC-NC structure. The experimental investigations of the scaled models of 1:4 were conducted. The experimental results verified the reliability of the new structures. The thickness of the UHPC layer and the steel reinforcement ratio was considered to calculate the cracking load of the structure by the finite element method. The results show that the relative errors between the proposed method and the FEM are less than 11%. When the bending-shear combination effect is considered, the relative errors between the two methods are less than 10%. The reliability and applicability of the connection structure were verified, which provides a reference for the design and engineering application. [ABSTRACT FROM AUTHOR]