"Jangheon" in Jangheon Engineering & Construction(CEO Seo Seong Yeol) is a name derived from the posthumous title of King Sejong. It reflects the company’s determination to develop new bridge technologies in Korea, just as King Sejong invented Hangeul. As a leading company in the bridge sector, Jangheon Engineering & Construction lives up to its name by holding three New Excellent Technology certificates related to girders. These are DR Girder (No. 582), Pre-tensioned PSC I-type Girder (No. 752), and Nodular Girder (No. 812). Based on these innovations, the company achieved the No.1 ranking in the utilization performance of New Excellent Technology in the construction field for two consecutive years, 2015 and 2016. Last year, it ranked 8th in the utilization performance with its flagship technology, the so-called "DR Girder" (13.4 billion KRW, 33 cases). The official name of the DR Girder is "A method for prestressed concrete girders using an anchoring system that enables de-tensioning and re-tensioning of tendons at the girder ends.”

Unlike general PSC girders, DR girder is known for improving structural efficiency by more than 10% by introducing prestress in a non-composite state. It can be applied to spans of up to 55 meters, and by prefabricating the deck slab and cross beams at the factory, construction processes are simplified, enhancing both constructability and safety. Since a tension adjustment system is installed, it is also advantageous for maintenance. Among PSC girder bridge types, it allows for the lowest girder height with the longest span. A representative from Jangheon Engineering & Construction explained, “Through de-tensioning and re-tensioning, the technology enables long spans with low girder height at low cost and high efficiency, while also allowing rapid and simple construction.”

Jangheon Engineering & Construction's latest girder construction method, 'Nodular Girder,' is a next-generation flagship technology. Last year, it ranked 30th in utilization performance of New Excellent Technology(48 billion KRW). Its official name is "A rapid construction method for PSC box girder bridges using factory-manufactured pretensioned concrete web members and nodular components." The nodular girder improves the weak lateral stiffness of I-shaped girders by adopting a box-shaped cross-section reinforced with tensioned steel bars. By slimming down the thick web of the box cross-section to 150mm, it reduces dead load, while the use of tensioned steel bars enhances shear performance.

The core components, including the nodules, box cross-section, and end blocks, can all be precast in the factory, ensuring consistent quality and minimizing on-site work. Using nodules—named after bamboo joints—the precast components are connected and the cross-section is strengthened. The upper and lower slabs are cast on-site and integrated with the precast members.

A key feature of the Nodular Girder is that its nodules, which act as segmented girder elements, allow for a variety of construction applications, including curved girders. Notably, it is regarded as the most economical method for bridges with spans greater than 50 meters. Jangheon Engineering & Construction is also exploring overseas expansion with the Nodular Girder. A company representative stated, “We plan to steadily build up domestic construction records and prioritize the Chinese and Japanese markets.”

Source: Daehan Gyeongje, Reporter Kim Tae Hyung
(translated from Korean article)