On June 9, Hyundai Steel introduced its PI girder bridge technology and held a public test demonstration.
The new technology was developed jointly with the Korea Road Association and patent company Hongji after the founding of the Bridge Construction Development Council for its development. The PI girder (a double-composite steel girder shaped like the symbol ‘π’) is a steel composited bridge comprised of a pair of I-shaped steel girders and a horizontal plate, made of high-strength concrete of optimized thickness that connects the two girders.
The public demonstration began with an introduction of the new technology, followed by a performance test. In the performance test, a load of 900 kN (1.5 times the supported load) was applied to the PI girder using a hydraulic accelerator. Even under this high amount of pressure, the PI girder maintained its integrity, due to the strength of the girder’s concrete and composite structural steel plate. Based on its design, it is estimated that the girder can withstand a load pressure of up to 1,500 kN. The Bridge Construction Development Council will continue to conduct tests to verify the safety and economic feasibility of the PI girder.
The patent aims to create new demands for structural backplates, expand the steel bridge market, and create mutually beneficial cooperation by supporting research by SMEs. The PI girder, developed from July 15, 2019 to July 2020, shows a 10-20% reduced construction cost compared to other methods, such as the steel composite girder and the improved steel composite girder. Hyundai Steel expects to commercialize its PI girder from 2022, thereby generating new fixed demand for more than 2,000 tons of structural heavy plates per year. Additionally, Hyundai Steel plans to continue to perform value engineering (VE) activities to maximize customer value.