Abstract：In order to investigate the basic mechanical performances of a composite deck with Steel and ultra-thin UHPC (Ultra-high Performance Concrete)-TPO (Thin Polymer Overlay), 5 pieces of steel- UHPC-TPO composite plate were designed, and the static bending and fatigue bending tests were carried. The static tests show that the cracking strengths of UHPC layers are between 22.1 and 24.3MPa. Under the action of negative moments, TPO enters the nonlinear phase prior to the UHPC. The fatigue tests show that for the new composite deck applied to the Humen suspension bridge, the fatigue life of the UHPC can be up to 925.7 million times, and no fatigue cracking appears in TPO under the design stress. After the fatigue loading, the residual flexural strength of the composite plates are about 26.9kN, and the bending stiffness of the composite plates is only decreased by 13% compared with the static test results. The research results indicate that the steel-ultra thin UHPC-TPO composite deck has excellent flexural performances.
