ABSTRACT
In order to investigate the axial tension behavior and crack resistance performance of steel-coarse aggregates UHPC composite bridge deck, the reinforced coarse aggregates UHPC slab, the steel plate- coarse aggregates UHPC composite slabs without and with bulb flat rib subjected to axial load were designed and tested. The test results show that the crack feature of coarse aggregates UHPC layer is composed of several micro-cracks, which is different from that of normal concrete. And the crack distribution is associated with the arrangement of transverse rebars. Considering the durability of UHPC layer, nominal UHPC tensile stress of 9 MPa is suggested as the design stress for steel-coarse aggregates UHPC composite slab. The axial load-carrying capacity of steel-coarse aggregates UHPC composite slab with bulb flat rib are 4.5 times, 3 times, 2.7times and 2.7 times larger than that of reinforced coarse aggregates UHPC slab corresponding to UHPC crack width of 0.05mm, 0.1mm, 0.15mm, and 0.2mm, respectively. Based on different steel plate tensile stress levels within yielding, the axial load-carrying capacity of steel-coarse aggregates UHPC composite slab presents positive correlation with the steel plate area.
