The first prefabricated steel-UHPC light-duty composite beam vehicle flyover in Yunnan Province completed the hoisting

On April 25, at the construction site of the Hongpo flyover of Changbao Expressway, the stable erection of 6-piece steel-UHPC lightweight composite beams was completed. This marks the first prefabricated steel-UHPC light-duty composite beam vehicle flyover in Yunnan Province to complete the upper structure hoisting and enter a new construction stage.

The Hongpo flyover on Changbao Expressway is an overpass for vehicles with a total of 6 composite beams, using a 3×30-meter steel-UHPC composite beam structure system. During the construction process, facing the application of new technologies, the Changbao Expressway team conducted technical research through the QC team. The mechanical performance of the UHPC joints in the negative moment area on the top of the pier and the mechanical performance of the longitudinal UHPC joints between the piers are experimentally studied. In addition, a pull-out and non-shear-resistant welding studs have been installed in the negative moment area on the top of a span of piers, and related model comparison tests are underway.

The reporter learned that the prefabricated steel-UHPC lightweight composite beam technology has the advantages of saving costs, reducing environmental pollution, high safety, and quick construction methods. The bridge deck is made of ultra-high-performance concrete, which not only has durability and long service period, improves material utilization, but also enhances crack resistance, prevents water seepage and pollutes the lower steel girders, and achieves zero maintenance. In addition, the self-weight of the prefabricated prefabricated parts is only 60-70% of the traditional steel plate beam-ordinary concrete composite structure under the same strength bearing conditions, and the whole span can be hoisted. Only the vertical and horizontal joints need to be poured at the construction site, no new equipment investment is needed, and the combined structure design is simple, and there is no need to weld steel plates on site.

It is reported that during the construction of the Changbao Expressway, the Changbao Expressway team actively researched and promoted the application of new technologies, new processes, new materials, and new equipment, achieving technological hematopoiesis and innovation-driven.