Segmental precast composite-material composite-slab composite beam and construction method thereof

A segmental precast composite-material composite-slab composite beam structure, comprising a segmental precast orthotropic composite top slab, a web, a bottom slab, and a wet joint between segments, wherein an orthotropic composite-material composite top slab is composed of an orthotropic slab and an ultra-high-performance concrete layer (UHPC), and forms a segmental precast composite-material composite-slab composite beam structure with the web and the bottom slab;

• the composite beam structure sequentially comprises the bottom slab, the web, the orthotropic top slab, a shear key, a reinforced UHPC structural layer from bottom to top;
• the bottom slab, the web, the orthotropic top slab and subsidiary members thereof are manufactured in elements in a plant and pre-assembled into a main beam segment, then the shear key is installed on and a reinforcing mesh is laid on the orthotropic top slab, and a UHPC layer is cast and cured to form a precast composite-material composite-slab composite beam segment, which is then transported, hoisted and assembled as a whole, and the connection of the UHPC structural layers between the segments is completed by casting a transverse wet joints in place.